Mrs. Daniel s Geometry Vocab List

Transcription

1 Mrs. Daniel s Geometry Vocab List

2 Geometry Definition: a branch of mathematics concerned with questions of shape, size, relative position of figures, and the properties of space.

3 Refectional Symmetry Definition: All of the points on one side of the line exactly match with all of the points on the other side of the line.

4 Definition: looks that same after you turn the image around a point by less than 180 degrees. The number of times you can turn the image determines the type of rotational symmetry. Rotational Symmetry

5 Point Definition: Location only; it has no size. How to Name: One capital letter. Example: P

6 Line Definition: Straight continuous arrangement of infinitely many points. How to Name: Two capital letters with a line with 2 arrows above it. Example:

7 Plane Definition: Flat surface that extends infinitely along its length and width. How to Name: One capital script (cursive) letter. Example: M

8 Collinear Definition:On the same line

9 Coplanar Definition:On the same plane

10 Ray Definition:A point on a line, and all the points that lie on one side of this point. How to Name: Two capital letters and a line with one arrow above. The endpoint must be the first letter. Example:

11 Line Segment Definition: Part of line. Does not extend indefinitely. How to Name: Two capital letters and a line on top. Example:

12 Midpoint Definition:Point on a line segment that is the same distance from both end points. How to Name: One capital letter Example: C

13 Congruent Definition: Equal. The same length. The same size. The same measure. Drawn with hash marks.

14 Bisects Definition Divides into two equal, congruent parts. Line: divides into two congruent segments Angle: divides into two congruent angles

15 Angle Definition: Formed by two rays that share a common endpoint. How to Name: One or three letters. Angle symbol ( ) in front. Example: B or ABC

16 Vertex Definition: Common endpoint of the two rays in an angle

17 Perpendicular Definition: Lines that meet at a 90 degree angle. Symbol: For example:

18 Parallel Definition: Lines that never intersect (cross/touch). Symbol: Example:

19 Complementary Angles Definition: 2 angles that add up to 90 degrees.

20 Supplementary Angles Definition: 2 angles that add up to 180 degrees.

21 Linear Pair of Angles Definition: Two angles on one line. Sum to 180 degrees.

22 Right Angle Definition: Angle measure of exactly 90 degrees. Symbol: Drawn with a box

23 Acute Angle Definition: Angle measure of less than 90 degrees.

24 Obtuse Angle Definition: Angle measure of more than 90 degrees, but less than 180.

25 Polygon Definition: A closed figure. How to Name: All capital letters. Use as many letter as sides to the polygon. Some Examples:

26 Diagonal Definition: a line segment drawn from one vertex to another in a polygon.

27 Concave Definition: Polygon dips inward (Some diagonals can be drawn outside the shape).

28 Convex Definition: Polygon only points outward. (No diagonals can be drawn outside the shape).

29 Regular Polygon Definition: A closed figure, with congruent sides and congruent angles. All sides and angles marked congruent.

30 Perimeter Definition: Sum of the lengths of the sides. Perimeter = 26cm

31 Right Triangle Definition: A triangle with one 90 degree angle. Marked with box

32 Acute Triangle Definition: A triangle with three acute angles.

33 Obtuse Triangle Definition: A triangle with one obtuse angle.

34 Scalene Triangle Definition: Triangle with no congruent sides. Each side is marked with a different number of hash marks.

35 Isosceles Triangle Definition: Triangle with at least two congruent sides and two congruent angles. Picture: Marked with two congruent sides and two congruent angles.

36 Equilateral Triangle Definition: Triangle with three congruent sides and angles. Marked with three congruent sides and three congruent angles.

37 Quadrilateral Definition: Any closed four sided figure. Some Examples:

38 Trapezoid Definition: A quadrilateral with exactly one pair of parallel sides. Opposite sides marked parallel.

39 Kite Definition: A quadrilateral with two distinct pairs of consecutive congruent sides. Sides next to each other marked congruent.

40 Parallelogram Definition: A quadrilateral with two pairs of parallel sides. Marked parallel and congruent.

41 Rhombus Definition: Two pairs of parallel sides and 4 congruent sides. Marked parallel and congruent.

42 Rectangle Definition: Two pairs of parallel sides and 4 congruent angles Marked parallel, congruent and 4 right angles.

43 Square Definition: 4 congruent sides and 4 congruent angles Marked parallel, congruent and four right angles.

44 Circle Definition: a set of all points in a plane at a given distance from a given point (center/origin).

45 Radius Definition: The given distance from center/origin of the circle to the edge.

46 Diameter Definition: A chord that passes through the origin/center. Picture:

47 Chord Definition: A line segment whose endpoints lie on the circle. The diameter is the longest chord.

48 Tangent Definition: A line that touches (intersects) the circle only once. The point the circle touches the circle is named the point of tangency.

49 Semicircle Definition: Half of a circle.

50 Space Definition: the set of ALL points; not contained to a flat surface. Space is threedimensional (3 D).

51 Cylinder

52 Prism

53 Sphere

54 Cone

55 Pyramid

56 Hemisphere