| A | B |
|---|
| line | connects two points and continues forever in two directions |
| ray | has one endpoint and continues forever in one direction |
| point | identifies location in space |
| line segment | a piece of a line with two endpoints |
| angle | made of two rays that connects at a common endpoint |
| acute angle | an angle with more than 0 degrees but less than 90 degrees |
| right angle | an angle that has exactly 90 degrees |
| obtuse angle | an angle that is greater than 90 degrees, but less than 180 degrees |
| straight angle | has exactly 180 degrees |
| vertex | the point of the angle where the two rays meet |
| adjacent angle | angles that share a ray and common endpoint |
| vertical angle | angles created by two intersecting lines that share a vertex but are in opposite directions |
| complementary angles | angles that add to 90 degrees |
| supplementary angles | angles that add to 180 degrees |
| right triangle | a triangle with one right angle |
| obtuse triangle | a triangle with one obtuse angle |
| acute triangle | a triangle with 3 acute angles |
| scalene triangle | a triangle with no congruent sides and no congruent angles |
| isosceles triangle | a triangle with two congruent sides and two congruent angles |
| equilateral triangle | a triangle with three congruent sides and three congruent angles (all 60 degrees) |
| congruent | same size and same shape |
| polygon | a closed figure with three or more line segments |
| regular polygon | a polygon with all congruent sides and all congruent angles |
| quadrilateral | a four sided polygon whose angles total 360 degrees |
| pentagon | a five sided polygon |
| hexagon | a six sided polygon |
| octagon | an eight sided polygon |
| decagon | a ten sided polygon |
| parallelogram | a quadrilateral with two pairs of parallel sides |
| rhombus | a parallelogram with four congruent sides |
| rectangle | a parallelogram with four right angles |
| square | a parallelogram with four right angles an four congruent sides |
| trapezoid | a quadrilateral with one pair of parallel sides |
| triangle | a three sided polygon whose angles total 180 degrees |
| parallel lines | lines that never intersect |
| perpendicular lines | lines that form a right angle |
| segment bisector | a ray, line or line segment that cuts a segment into two conrgruent parts |
| angle bisector | a ray, line or line segment that cuts an angle into two congruent parts |
| perpendicular bisector | a ray, line or line segment that cuts a segment into two congruent parts and forms a right angle |
