1. Point—names a location in space.
2. Line—perfectly straight and extends forever in two directions.
3. Plane—a perfectly flat surface that extends forever in all directions
4. segment—part of a line between two points
5. Ray—part of a line that starts at one point and extends forever in one direction
6. Angle---formed by two rays with a common endpoint
7. Right angle—measures 90 degrees
8. acute angle—an angle measuring less than 90 degrees
9. obtuse angle—an angle measuring more than 90 degrees and less than 180 degrees.
10. Complementary angles—two angles whose sum equals 90 degrees.
11. supplementary—two angles whose sum is 180 degrees.
12. congruent—same size and shape.
13. vertical angles—two pairs of congruent angles formed by intersecting lines.
14. straight angle—an angle that measures 180 degrees.
15. vertex—the common endpoint at the intersection of two rays
16. parallel lines--Lines in a plane that never meet or intersect.
17. Perpendicular lines—lines that intersect at 90 degrees, forming right angles.
18. transversal—a line that intersects any two or more other lines, not necessarily at 90 degree angles.
19. Triangle sum theorem—This theorem states that the measures of t he angles in the triangle add up
to 180 degrees.
20. Acute triangle –a triangle in which all angles measure less than 90 degrees (all angles are acute.)
21. right triangle—a triangle with one right angle.
22. equilateral triangle—A triangle with three equal sides and three equal angles.
23. Obtuse triangle—a triangle containing one obtuse angle.
24. Isosceles triangle—a triangle with two equal sides and two equal angles.
25. scalene—a triangle with sides of different lengths (and no two angles are the same.)
26. polygon—a closed plane figure formed by three or more line segments. The line segments never
cross but meet at their endpoints.
27. regular polygon—a polygon with congruent sides and angles.
28. Trapezoid-- A quadrilateral with one pair of parallel sides.
29. parallelogram—a quadrilateral with two pairs of congruent, parallel sides.
30. rectangle—a parallelogram with four right angles.
31. rhombus—a parallelogram with all sides equal and congruent
32. square—a rectangle with 4 congruent sides and 4 right angles.
33. x-axis—the horizontal number line used on a coordinate graph
34. y-axis—the vertical number line used on a coordinate graph.
35. x-coordinate—the value on the x-axis used to locate a point on the coordinate graph. It is the first
value in an ordered pair.
36. y-coordinate—the value on the y axis used to locate a point on the coordinate graph. It is the
second value in an ordered pair.
37. Quadrant—one of the four regions formed by the intersection of the axes of a coordinate graph.
38. Similar figures—figures that have the same shape but different sizes. Their sides are proportional,
while their corresponding angles are equal.
39. corresponding sides or angles—in similar or congruent polygons ,these sides or angles match up to
one another. (You match a side/angle from one polygon to a side/angle in the other polygon.)
40. Perimeter—the distance around a figure.
41. Area—the number of square units needed to cover a given surface
42. Circle—set of points equal in distance from a single point called the center.
43. Radius—half the diameter of a circle; the distance from the center of the circle to the circle itself.
44. Diameter—a line segment that passes through the center of a circle and has it endpoints on the
circle
45. Circumference—the distance around a circle (the perimeter of a circle.)
46. chord—a line segment which connects two points on a circle, not necessarily through the center.
47. arc—an unbroken part or piece of a circle.
48. central angle—an angle formed by two radii with its vertex at the center of a circle.
49. Volume—the number of cubic units required to fill a 3 dimensional object
50. Prism—a solid figure that has two congruent parallel polygons as its bases. Its sides are
parallelograms.
51. Pyramid—a solid figure that has triangles for its sides and a polygon as its base.
50. vertical angles—angles formed by intersecting lines; they are opposite each other and equal in
measure.