NAME DATE PERIOD. Find the sum of the measures of the interior angles of each convex polygon. 1. nonagon 2. heptagon 3. decagon

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1 8-1 kills ractice Angles of olgons Find the sum of the measures of the interior angles of each convex polgon. 1. nonagon 2. heptagon 3. decagon he measure of an interior angle of a regular polgon is given. Find the number of sides in each polgon Find the measure of each interior angle using the given information. Lesson A B 8. (2x 15) x L M (2x 20) (3x 10) x D (2x 15) C 2x (2x 10) 9. quadrilateral W with, 10. hexagon DEFGHI with W, m 2x 16, D E G H, F I, m x 14 md 7x, mf 4x D E I F W H G Find the measures of an interior angle and an exterior angle for each regular polgon. 11. quadrilateral 12. pentagon 13. dodecagon Find the measures of an interior angle and an exterior angle given the number of sides of each regular polgon. ound to the nearest tenth if necessar Glencoe/McGraw-Hill 419 Glencoe Geometr

2 8-2 Complete each statement about LM. Justif our answer. 1. L ractice arallelograms? L M 2. LM? 3. LM? 4. L is supplementar to?. 5. LM? ALGEBA se to find each measure or value. 6. m 7. m 8. m 9. b B 23 4b 1 COODIAE GEOMEY Find the coordinates of the intersection of the diagonals of parallelogram YZ given each set of vertices. 10. (2, 5), (3, 3), Y(2, 3), Z(3, 1) 11. (2, 3), (1, 2), Y(5, 7), Z(4, 2) 12. OOF Write a paragraph proof of the following. Given: and V rove: V V 13. COCIO Mr. odriquez used the parallelogram at the right to design a herringbone pattern for a paving stone. He will use the paving stone for a sidewalk. If m1 is 130, find m2, m3, and m Glencoe/McGraw-Hill 426 Glencoe Geometr

3 8-3 ractice ests for arallelograms Determine whether each quadrilateral is a parallelogram. Justif our answer COODIAE GEOMEY Determine whether a figure with the given vertices is a parallelogram. se the method indicated. 5. (5, 1), (2, 2), F(1, 3), (2, 2); lope Formula 6. (2, 5), O(1, 3), M(3, 4), Y(6, 2); Distance and lope Formula ALGEBA Find x and so that each quadrilateral is a parallelogram (5x 29) (3 15) (7x 11) (5 9) 4x x x x 6 2x x ILE DEIG he pattern shown in the figure is to consist of congruent parallelograms. How can the designer be certain that the shapes are parallelograms? Glencoe/McGraw-Hill 432 Glencoe Geometr

4 8-4 ractice ectangles ALGEBA is a rectangle. 1. If Z x 21 and Z 3x 15, find. 2. If Z 3x 8 and Z 6x 28, find Z. Z 3. If 5x 8 and Z 4x 1, find Z. 4. If m 3x 6 and m 5x 4, find m. 5. If m x 2 9 and m 2x 44, find x. 6. If m x 2 1 and m 3x 9, find m. GHJK is a rectangle. Find each measure if m m2 8. m3 9. m4 10. m5 G 2 K 1 H J 11. m6 12. m7 COODIAE GEOMEY Determine whether BGHL is a rectangle given each set of vertices. Justif our answer. 13. B(4, 3), G(2, 4), H(1, 2), L(1, 3) 14. B(4, 5), G(6, 0), H(3, 6), L(7, 1) 15. B(0, 5), G(4, 7), H(5, 4), L(1, 2) 16. LADCAIG Huntington ark officials approved a rectangular plot of land for a Japanese Zen garden. Is it sufficient to know that opposite sides of the garden plot are congruent and parallel to determine that the garden plot is rectangular? Explain. Glencoe/McGraw-Hill 438 Glencoe Geometr

5 8-5 ractice hombi and quares se rhombus YZ with K 4 1, ZK 7 14, K 3x 1, and YK 2x Find Y. 2. Find Z. K Y Z 3. Find Y. 4. Find mykz. se rhombus M with 32, A 4x 1, and AM 9x 6. A 5. Find A. 6. Find ma. M 7. Find mm. 8. Find M. COODIAE GEOMEY Given each set of vertices, determine whether BEFG is a rhombus, a rectangle, or a square. List all that appl. Explain our reasoning. 9. B(9, 1), E(2, 3), F(12, 2), G(1, 4) 10. B(1, 3), E(7, 3), F(1, 9), G(5, 3) 11. B(4, 5), E(1, 5), F(7, 1), G(2, 1) 12. EELAIO he figure is an example of a tessellation. se a ruler or protractor to measure the shapes and then name the quadrilaterals used to form the figure. Glencoe/McGraw-Hill 444 Glencoe Geometr

6 8-6 kills ractice rapezoids COODIAE GEOMEY ABCD is a quadrilateral with vertices A(4, 3), B(3, 3), C(6, 4), D(7, 4). 1. Verif that ABCD is a trapezoid. 2. Determine whether ABCD is an isosceles trapezoid. Explain. Lesson 8-6 COODIAE GEOMEY EFGH is a quadrilateral with vertices E(1, 3), F(5, 0), G(8, 5), H(4, 4). 3. Verif that EFGH is a trapezoid. 4. Determine whether EFGH is an isosceles trapezoid. Explain. COODIAE GEOMEY LM is a quadrilateral with vertices L(1, 3), M(4, 1), (6, 3), (0, 7). 5. Verif that LM is a trapezoid. 6. Determine whether LM is an isosceles trapezoid. Explain. ALGEBA Find the missing measure(s) for the given trapezoid. 7. For trapezoid HJKL, and are 8. For trapezoid WXYZ, and are midpoints of the legs. Find HJ. midpoints of the legs. Find WX. L 9. For trapezoid DEFG, and are 10. For isosceles trapezoid, find the midpoints of the legs. Find, me, length of the median, m, and m. and mg. D H J E 85 G 14 F K Z W X Y Glencoe/McGraw-Hill 449 Glencoe Geometr

7 8-7 ractice Coordinate roof with uadrilaterals osition and label each quadrilateral on the coordinate plane. 1. parallelogram with side length b units 2. isosceles trapezoid with height b units, and height a units bases 2c a units and 2c a units D(c, a) C(b c, a) D(a, b) C(2c, b) A(0, 0) B(b, 0) A(0, 0) B(a 2c, 0) ame the missing coordinates for each quadrilateral. 3. parallelogram 4. isosceles trapezoid L(c,?) K(?, a) Y(?,?) Z(b, c) O H(0, 0) J(2b, 0) x X(?,?) O W(a, 0) x osition and label the figure on the coordinate plane. hen write a coordinate proof for the following. 5. he opposite sides of a parallelogram are congruent. D(b, c) C(a b, c) A(0, 0) B(a, 0) 6. HEAE A stage is in the shape of a trapezoid. Write a coordinate proof to prove that and F are parallel. F(0, 25) (30, 25) O (10, 0) (20, 0) x Glencoe/McGraw-Hill 456 Glencoe Geometr

8 Answers (Lesson 8-1) Lesson kills ractice Angles of olgons Find the sum of the measures of the interior angles of each convex polgon. 1. nonagon 2. heptagon 3. decagon he measure of an interior angle of a regular polgon is given. Find the number of sides in each polgon Find the measure of each interior angle using the given information. 7. A B 8. (2x 15) x L M (2x 20) (3x 10) D x (2x 15) C ma 115, mb 65, ml 100, mm 110, mc 115, md 65 m 70, m 80 2x (2x 10) 9. quadrilateral W with, 10. hexagon DEFGHI with W, m 2x 16, D E G H, F I, m x 14 md 7x, mf 4x D E I F W H G m 116, m 116, md 140, me 140, m 64, mw 64 mf 80, mg 140, mh 140, mi 80 Find the measures of an interior angle and an exterior angle for each regular polgon. 11. quadrilateral 12. pentagon 13. dodecagon 90, , , 30 Find the measures of an interior angle and an exterior angle given the number of sides of each regular polgon. ound to the nearest tenth if necessar , , , 27.7 Glencoe/McGraw-Hill 419 Glencoe Geometr Answers 8-1 ractice (Average) Angles of olgons Find the sum of the measures of the interior angles of each convex polgon gon gon gon he measure of an interior angle of a regular polgon is given. Find the number of sides in each polgon Find the measure of each interior angle using the given information. 7. J K 8. quadrilateral with (2x 15) (3x 20) m 6x 4, m 2x 8 (x 15) x M mj 115, mk 130, mm 50, m 65 m 128, m 52, m 128, m 52 Find the measures of an interior angle and an exterior angle for each regular polgon. ound to the nearest tenth if necessar gon gon gon 157.5, , , 12 Find the measures of an interior angle and an exterior angle given the number of sides of each regular polgon. ound to the nearest tenth if necessar , , , CYALLOGAHY Crstals are classified according to seven crstal sstems. he basis of the classification is the shapes of the faces of the crstal. urquoise belongs to the triclinic sstem. Each of the six faces of turquoise is in the shape of a parallelogram. Find the sum of the measures of the interior angles of one such face. 360 Glencoe/McGraw-Hill 420 Glencoe Geometr Glencoe/McGraw-Hill A3 Glencoe Geometr

9 Answers (Lesson 8-2) Lesson kills ractice arallelograms Complete each statement about DEFG. Justif our answer. D H 1. DG? EF; opp. sides of are. G F E 2. DE? GF; opp. sides of are. 3. GH? EH; diag.of bisect each other. 4. DEF? FGD; opp. of are. 5. EFG is supplementar to?. DEF or FGD; cons. in are suppl. 6. DGE? FEG; diag.of separates into 2 s. ALGEBA se WXYZ to find each measure or value. W A 7. mxyz mwzy Z 9. mwxy a a 70 X Y COODIAE GEOMEY Find the coordinates of the intersection of the diagonals of parallelogram HJKL given each set of vertices. 11. H(1, 1), J(2, 3), K(6, 3), L(5, 1) 12. H(1, 4), J(3, 3), K(3, 2), L(1, 1) (3.5, 2) (1, 1) 13. OOF Write a paragraph proof of the theorem Consecutive angles in a parallelogram are supplementar. Given: ABCD rove: A and B are supplementar. B and C are supplementar. C and D are supplementar. D and A are supplementar. D C roof: We are given ABCD, so we know that AB CD and BC DA b the definition of a parallelogram. We also know that if two parallel lines are cut b a transversal, then consecutive interior angles are supplementar. o, A and B, B and C, C and D, and D and A are pairs of supplementar angles. A B Glencoe/McGraw-Hill 425 Glencoe Geometr 8-2 ractice (Average) arallelograms Complete each statement about LM. Justif our answer. 1. L? ; diag.of bisect each other. L M 2. LM? L; opp. of are. 3. LM? M; diag.of separates into 2 s. 4. L is supplementar to?. M or LM; cons. in are suppl. 5. LM? ; opp. sides of are. ALGEBA se to find each measure or value. 6. m m 8. m b B 23 4b 1 COODIAE GEOMEY Find the coordinates of the intersection of the diagonals of parallelogram YZ given each set of vertices. 10. (2, 5), (3, 3), Y(2, 3), Z(3, 1) 11. (2, 3), (1, 2), Y(5, 7), Z(4, 2) (0, 1) (1.5, 2) 12. OOF Write a paragraph proof of the following. Given: and V rove: V roof: We are given and V. ince opposite angles of a parallelogram are congruent, V and. ince congruence of angles is transitive, V b the ransitive ropert of Congruence. V 13. COCIO Mr. odriquez used the parallelogram at the right to design a herringbone pattern for a paving stone. He will use the paving stone for a sidewalk. If m1 is 130, find m2, m3, and m4. 50, 130, Glencoe/McGraw-Hill 426 Glencoe Geometr Glencoe/McGraw-Hill A6 Glencoe Geometr

10 Answers (Lesson 8-3) Lesson kills ractice ests for arallelograms Determine whether each quadrilateral is a parallelogram. Justif our answer Yes; a pair of opposite sides Yes; both pairs of opposite is parallel and congruent. angles are congruent o; none of the tests for Yes; both pairs of opposite sides parallelograms is fulfilled. are congruent. COODIAE GEOMEY Determine whether a figure with the given vertices is a parallelogram. se the method indicated. 5. (0, 0), (3, 4), (7, 4), Y(4, 0); lope Formula es 6. (2, 1), (1, 3), (2, 0), Z(1, 2); Distance and lope Formula es 7. W(2, 5), (3, 3), Y(2, 3), (3, 1); Midpoint Formula no ALGEBA Find x and so that each quadrilateral is a parallelogram x x x 16 x 24, 19 x 3, 14 3x 10. (4x 35) ( 15) 11. x (2 5) (3x 10) 3x 14 x 45, 20 x 17, 9 Glencoe/McGraw-Hill 431 Glencoe Geometr Answers 8-3 ractice (Average) ests for arallelograms Determine whether each quadrilateral is a parallelogram. Justif our answer Yes; the diagonals bisect o; none of the tests for each other. parallelograms is fulfilled Yes; both pairs of opposite o; none of the tests for angles are congruent. parallelograms is fulfilled. COODIAE GEOMEY Determine whether a figure with the given vertices is a parallelogram. se the method indicated. 5. (5, 1), (2, 2), F(1, 3), (2, 2); lope Formula no 6. (2, 5), O(1, 3), M(3, 4), Y(6, 2); Distance and lope Formula es ALGEBA Find x and so that each quadrilateral is a parallelogram (5x 29) (5 9) 8. 4x 2 3x (3 15) (7x 11) x 20, 12 x 6, x 10. 2x 6 x x 6 x 3, 2 x 2, ILE DEIG he pattern shown in the figure is to consist of congruent parallelograms. How can the designer be certain that the shapes are parallelograms? ample answer: Confirm that both pairs of opposite s are. Glencoe/McGraw-Hill 432 Glencoe Geometr Glencoe/McGraw-Hill A9 Glencoe Geometr

11 Answers (Lesson 8-4) Lesson kills ractice ectangles ALGEBA ABCD is a rectangle. 1. If AC 2x 13 and DB 4x 1, find x. 7 A E B D C 2. If AC x 3 and DB 3x 19, find AC If AE 3x 3 and EC 5x 15, find AC If DE 6x 7 and AE 4x 9, find DB If mdac 2x 4 and mbac 3x 1, find x If mbdc 7x 1 and madb 9x 7, find mbdc If mabd x 2 7 and mcdb 4x 5, find x If mbac x 2 3 and mcad x 15, find mbac. 67 or 84 is a rectangle. Find each measure if m m m m m m m m m9 80 COODIAE GEOMEY Determine whether XY is a rectangle given each set of vertices. Justif our answer. 17. (3, 2), (4, 2), X(2, 4), Y(3, 0) o; sample answer: Angles are not right angles. 18. (6, 3), (0, 6), X(2, 2), Y(4, 1) Yes; sample answer: Opposite sides are congruent and diagonals are congruent. 19. (4, 1), (3, 1), X(3, 2), Y(2, 4) Yes; sample answer: Opposite sides are parallel and consecutive sides are perpendicular. Glencoe/McGraw-Hill 437 Glencoe Geometr 8-4 ractice (Average) ectangles ALGEBA is a rectangle. 1. If Z x 21 and Z 3x 15, find. 78 Z 2. If Z 3x 8 and Z 6x 28, find Z If 5x 8 and Z 4x 1, find Z If m 3x 6 and m 5x 4, find m If m x 2 9 and m 2x 44, find x. 5 or 7 6. If m x 2 1 and m 3x 9, find m. 24 or 3 GHJK is a rectangle. Find each measure if m m m3 37 G 2 1 H 5 3 K 4 J m m m m7 74 COODIAE GEOMEY Determine whether BGHL is a rectangle given each set of vertices. Justif our answer. 13. B(4, 3), G(2, 4), H(1, 2), L(1, 3) Yes; sample answer: Opposite sides are parallel and consecutive sides are perpendicular. 14. B(4, 5), G(6, 0), H(3, 6), L(7, 1) Yes; sample answer: Opposite sides are congruent and diagonals are congruent. 15. B(0, 5), G(4, 7), H(5, 4), L(1, 2) o; sample answer: Diagonals are not congruent. 16. LADCAIG Huntington ark officials approved a rectangular plot of land for a Japanese Zen garden. Is it sufficient to know that opposite sides of the garden plot are congruent and parallel to determine that the garden plot is rectangular? Explain. o; if ou onl know that opposite sides are congruent and parallel, the most ou can conclude is that the plot is a parallelogram. Glencoe/McGraw-Hill 438 Glencoe Geometr Glencoe/McGraw-Hill A12 Glencoe Geometr

12 Answers (Lesson 8-5) Lesson kills ractice hombi and quares se rhombus DKLM with AM 4x, AK 5x 3, and DL 10. D K A 1. Find x. 2. Find AL. 3 5 M L 3. Find mkal. 4. Find DM se rhombus V with 5 2, 3 6, and V Find. 6. Find V V 7. Find mv. 8. Find mv Find m. 10. Find mv COODIAE GEOMEY Given each set of vertices, determine whether is a rhombus, a rectangle, or a square. List all that appl. Explain our reasoning. 11. (3, 5), (3, 1), (1, 1), (1, 5) hombus, rectangle, square; all sides are congruent and the diagonals are perpendicular and congruent. 12. (5, 12), (5, 12), (1, 4), (11, 4) hombus; all sides are congruent and the diagonals are perpendicular, but not congruent. 13. (6, 1), (4, 6), (2, 5), (8, 10) hombus; all sides are congruent and the diagonals are perpendicular, but not congruent. 14. (2, 4), (6, 8), (10, 2), (2, 6) one; opposite sides are congruent, but the diagonals are neither congruent nor perpendicular. Glencoe/McGraw-Hill 443 Glencoe Geometr Answers 8-5 ractice (Average) hombi and quares se rhombus YZ with K 4 1, ZK 7 14, K 3x 1, and YK 2x 6. K Y 1. Find Y. 2. Find Z Z 3. Find Y. 4. Find mykz se rhombus M with 32, A 4x 1, and AM 9x 6. A 5. Find A. 6. Find ma M 7. Find mm. 8. Find M COODIAE GEOMEY Given each set of vertices, determine whether BEFG is a rhombus, a rectangle, or a square. List all that appl. Explain our reasoning. 9. B(9, 1), E(2, 3), F(12, 2), G(1, 4) hombus; all sides are congruent and the diagonals are perpendicular, but not congruent. 10. B(1, 3), E(7, 3), F(1, 9), G(5, 3) hombus, rectangle, square; all sides are congruent and the diagonals are perpendicular and congruent. 11. B(4, 5), E(1, 5), F(7, 1), G(2, 1) one; two of the opposite sides are not congruent. 12. EELAIO he figure is an example of a tessellation. se a ruler or protractor to measure the shapes and then name the quadrilaterals used to form the figure. he figure consists of 6 congruent rhombi. Glencoe/McGraw-Hill 444 Glencoe Geometr Glencoe/McGraw-Hill A15 Glencoe Geometr

13 Answers (Lesson 8-6) Lesson kills ractice rapezoids COODIAE GEOMEY ABCD is a quadrilateral with vertices A(4, 3), B(3, 3), C(6, 4), D(7, 4). 1. Verif that ABCD is a trapezoid. AB CD 2. Determine whether ABCD is an isosceles trapezoid. Explain. isosceles; AD 58 and BC 58 COODIAE GEOMEY EFGH is a quadrilateral with vertices E(1, 3), F(5, 0), G(8, 5), H(4, 4). 3. Verif that EFGH is a trapezoid. EF GH 4. Determine whether EFGH is an isosceles trapezoid. Explain. not isosceles; EH 26 and FG 34 COODIAE GEOMEY LM is a quadrilateral with vertices L(1, 3), M(4, 1), (6, 3), (0, 7). 5. Verif that LM is a trapezoid. LM 6. Determine whether LM is an isosceles trapezoid. Explain. not isosceles; L 17 and M 8 ALGEBA Find the missing measure(s) for the given trapezoid. 7. For trapezoid HJKL, and are 8. For trapezoid WXYZ, and are midpoints of the legs. Find HJ. 58 midpoints of the legs. Find WX. 5 H J 72 W X 12 L 86 K Z 19 Y 9. For trapezoid DEFG, and are 10. For isosceles trapezoid, find the midpoints of the legs. Find, me, length of the median, m, and m. and mg. 42 D E G 14 F 28, 95, , 125, Glencoe/McGraw-Hill 449 Glencoe Geometr 8-6 ractice (Average) rapezoids COODIAE GEOMEY is a quadrilateral with vertices (3, 3), (5, 1), (10, 2), (4, 9). 1. Verif that is a trapezoid. 2. Determine whether is an isosceles trapezoid. Explain. not isosceles; 37 and 34 COODIAE GEOMEY BGHJ is a quadrilateral with vertices B(9, 1), G(2, 3), H(12, 2), J(10, 6). 3. Verif that BGHJ is a trapezoid. BG HJ 4. Determine whether BGHJ is an isosceles trapezoid. Explain. not isosceles; BJ 50 and GH 125 ALGEBA Find the missing measure(s) for the given trapezoid. 5. For trapezoid CDEF, V and Y are 6. For trapezoid WL, B and C are midpoints of the legs. Find CD. 38 midpoints of the legs. Find L. 18 F 18 E V 28 Y 66 W 42 B C C D L 7. For trapezoid FGHI, K and M are 8. For isosceles trapezoid VZY, find the midpoints of the legs. Find FI, mf, length of the median, m, and mz. and mi. 51, 40, , 60, 120 F G 21 H K M 36 I 34 Y 5 Z 60 V 9. COCIO A set of stairs leading to the entrance of a building is designed in the shape of an isosceles trapezoid with the longer base at the bottom of the stairs and the shorter base at the top. If the bottom of the stairs is 21 feet wide and the top is 14, find the width of the stairs halfwa to the top ft 10. DEK O A carpenter needs to replace several trapezoid-shaped desktops in a classroom. he carpenter knows the lengths of both bases of the desktop. What other measurements, if an, does the carpenter need? ample answer: the measures of the base angles Glencoe/McGraw-Hill 450 Glencoe Geometr Glencoe/McGraw-Hill A18 Glencoe Geometr

14 Answers (Lesson 8-7) Lesson kills ractice Coordinate roof with uadrilaterals osition and label each quadrilateral on the coordinate plane. 1. rectangle with length 2a units and 2. isosceles trapezoid with height a units, height a units bases c b units and b c units D(0, a) C(2a, a) B(b, a) C(c, a) O A(0, 0) B(2a, 0) x O A(0, 0) B(b c, 0) x ame the missing coordinates for each quadrilateral. 3. rectangle C(c, a) 4. rectangle G(0, 2b) D(0, a) C(?,?) G(?,?) F(5b, 2b) O A(0, 0) (c, 0) x O D(0, 0) E(5b, 0) x 5. parallelogram (a b, c), (a, 0) 6. isosceles trapezoid W(a b, c), Y(0, c) (b, c) (?,?) Y(?,?) W(?, c) O (0, 0) (a,?) x O (a, 0) (b, 0) x osition and label the figure on the coordinate plane. hen write a coordinate proof for the following. 7. he segments joining the midpoints of the sides of a rhombus form a rectangle. Given: ABCD is a rhombus. M,,, and are the midpoints of AB, BC, CD, and DA, respectivel. rove: M is a rectangle. roof: M (a, b), (a, b), (a, b), and (a, b). b slope of M a slope of M a ( b b or 0 slope of b a) or undefined slope of b a ( b a) A(2a, 0) a ( ( b) a or 0 b) a or undefined M and have the same slope. M and also have the same slope. M is perpendicular to M. herefore, both pairs of opposite sides are parallel and consecutive sides are perpendicular. his means that M is a rectangle. M O B(0, 2b) D(0, 2b) C(2a, 0) x Glencoe/McGraw-Hill 455 Glencoe Geometr Answers 8-7 ractice (Average) Coordinate roof with uadrilaterals osition and label each quadrilateral on the coordinate plane. 1. parallelogram with side length b units 2. isosceles trapezoid with height b units, and height a units bases 2c a units and 2c a units D(c, a) C(b c, a) D(a, b) C(2c, b) O A(0, 0) B(b, 0) x O A(0, 0) B(a 2c, 0) x ame the missing coordinates for each quadrilateral. 3. parallelogram 4. isosceles trapezoid L(c,?) K(?, a) Y(?,?) Z(b, c) O H(0, 0) J(2b, 0) x X(?,?) O W(a, 0) x K(2b c, a), L(c, a) X(a, 0),Y(b, c) osition and label the figure on the coordinate plane. hen write a coordinate proof for the following. 5. he opposite sides of a parallelogram are congruent. Given: ABCD is a parallelogram. rove: AB CD, AD BC roof: AB (a ) 00 2 ( ) 0 2 a 2 or a CD [(a b) ] bc 2 ( ) c 2 a 2 or a AD (b ) 0c 2 ( ) 0 2 bc 2 2 AB [(a b) ] a 2 (c 0) 2 bc 2 2 AB CD and AD BC, so AB CD and AD BC O D(b, c) C(a b, c) A(0, 0) B(a, 0) x 6. HEAE A stage is in the shape of a trapezoid. Write a coordinate proof to prove that and F are parallel. Given: (10, 0), (20, 0), (30, 25), F(0, 25) rove: F roof: he slope of the slope of F F both have a slope of 0, F. and 0. ince and 0 O F(0, 25) (10, 0) (30, 25) (20, 0) x Glencoe/McGraw-Hill 456 Glencoe Geometr Glencoe/McGraw-Hill A21 Glencoe Geometr