ACT Math and Science - Problem Drill 11: Plane Geometry No. 1 of 10 1. Which geometric object has no dimensions, no length, width or thickness? (A) Angle (B) Line (C) Plane (D) Point (E) Polygon An angle has two dimensions. A line has one dimension. A plane has two dimensions. D. Correct! A point has no dimensions. A polygon has two dimensions. By definition, a point has no dimensions. The correct answer is (D).
No. 2 of 10 2. What type of angle is represented in the diagram? (A) Acute (B) Obtuse (C) Right (D) Straight (E) None of the above The measure of an acute angle is less than 90. B. Correct! The measure of an obtuse angle is between 90 and 180. The measure of a right angle is exactly 90. The measure of a straight angle is exactly 180. Review the definition for each type of angle and try again. The measure of the angle is more than 90 but less than 180. This is the definition of an obtuse angle. The correct answer is (B).
No. 3 of 10 3. Find the measure of an angle supplementary to K. K 68 (A) 22 (B) 68 (C) 112 (D) 202 (E) 292 Review the definition of supplementary angles. Review the definition of supplementary angles. C. Correct! You subtracted m K from 180 to find the answer. Review the definition of supplementary angles. Review the definition of supplementary angles. Subtract m K from 180 to find the measure of the supplementary angle. 180 m K 180 68 112 The correct answer is (C).
No. 4 of 10 4. Line v is parallel to line w. Which term describes the relationship between 5 and 7? 1 2 4 3 5 6 8 7 v w (A) Adjacent angles (B) Alternate exterior angles (C) Alternate interior angles (D) Corresponding angles (E) Vertical angles Review the definition of adjacent angles. Review the definition of alternate exterior angles. Review the definition of alternate interior angles. Review the definition of corresponding angles. E. Correct! Two angles that are across from each other at the intersection of two lines are vertical angles. By definition vertical angles are two angles that are across from each other at the intersection of two lines. The correct answer is (E).
No. 5 of 10 5. Which of the following is a regular polygon? (A) Circle (B) Equilateral triangle (C) Isosceles trapezoid (D) Kite (E) Rhombus Review the definition of a regular polygon and try again. B. Correct! All the side lengths of an equilateral triangle have equal lengths and all the angles are congruent. Review the definition of a regular polygon and try again. Review the definition of a regular polygon and try again. Review the definition of a regular polygon and try again. A regular polygon is a polygon where all the sides are congruent and all the angles are congruent. An equilateral triangle is a triangle with all sides congruent and all angles congruent. The correct answer is (B).
No. 6 of 10 6. The length of the radius of a circle is 9 centimeters. Find the length of the diameter of the circle. (A) 4.5 centimeters (B) 9 centimeters (C) 18 centimeters (D) 27 centimeters (E) 81 centimeters Review the definitions of radius and diameter and try again. Review the definitions of radius and diameter and try again. C. Correct! The diameter of a circle is double the length of its radius. Review the definitions of radius and diameter and try again. Review the definitions of radius and diameter and try again. The diameter of a circle is double the length of its radius. Double the radius of 9 centimeters to find the length. radius = 9 cm diameter = 2 radius = 2 9 = 18 cm The correct answer is (C).
No. 7 of 10 7. A figure that can be mapped onto itself with a 180 rotation has: (A) Point symmetry (B) Reflection symmetry (C) Supplementary angles (D) Complementary angles (E) None of the above A. Correct! This is the definition of point symmetry. Review the definition of reflection symmetry and try again. Review the definition of supplementary angles and try again. Review the definition of complementary angles and try again. Review the definition for each term and try again. If a figure can be mapped onto itself with a 180 rotation, then it has point symmetry. The correct answer is (A).
No. 8 of 10 8. How many lines of symmetry does this figure have? (A) 0 (B) 1 (C) 2 (D) 4 (E) 8 Review the definition of line of symmetry. Review the definition of line of symmetry. Review the definition of line of symmetry. D. Correct! The shape has 2 lines of symmetry through the concave vertices and 2 lines of symmetry through the midpoints of the sides. Review the definition of line of symmetry. Divide the first quantity by the second quantity then move the decimal two places to the right. The shape has 4 lines of symmetry. The correct answer is (D).
No. 9 of 10 9. Which transformation is shown in the diagram? (A) Vertical (B) Rotation (C) Adjacent (D) Reflection (E) Translation Review the different types of transformations and try again. B. Correct! The second figure is the result of rotating the first figure. Review the different types of transformations and try again. Review the different types of transformations and try again. Review the different types of transformations and try again. A rotation is a transformation that turns a figure around a fixed point. The correct answer is (B).
No. 10 of 10 10. Which strategy uses facts and theorems to arrive at a conclusion? (A) Deductive reasoning (B) Inductive reasoning (C) Plane geometry (D) Tessellation (E) Transformation A. Correct! This is the definition of deductive reasoning. Review the definition of inductive reasoning and try again. Review the definition of plane geometry and try again. Review the definition of tessellation and try again. Review the definition of transformation and try again. By definition deductive reasoning is a strategy that uses facts and theorems to arrive at a conclusion. The correct answer is (A).