| A | B |
|---|
| line segment | line with two endpoints |
| ray | line that goes forever in one direction |
| line | goes forever in two directions |
| vertex | point where two lines meet |
| acute angle | angle that has less than ninety degrees |
| obtuse angle | angle that has more than ninety degrees |
| right angle | angle that has exactly ninety degrees |
| intersecting lines | lines that cross |
| perpendicular lines | 2 lines that form a ninety degree angle |
| parallel lines | 2 lines going in the same direction that never meet |
| rectangle | plane figure with four right angles |
| square | a plane figure with four equal sides |
| triangle | geometric shape with three sides and three angles |
| hexagon | polygon with six sides |
| octagon | polygon with eight sides |
| pentagon | polygon with five sides |
| equilateral triangle | triangle with three equal sides |
| isosceles triangle | triangle with at least two equal sides |
| scalene triangle | triangle with no equal sides |
| circumference | distance around a circle |
