| A | B |
|---|
| line segment | a line with two endpoints |
| ray | a line with one endpoint |
| right angle | an angle that measures 90 degrees |
| obtuse angle | an agle that measures more than 90 degrees |
| acute angle | an angle that measures less than 90 degrees |
| perimeter | the distance around a shape |
| area | the measurement of space inside a shape |
| vertex | a point where two lines meet |
| triangle | a shape with 3 sides and 3 angles |
| square | a special kind of rectangle which all sides and all angles the same |
| rectangle | a four sided shape with 2 sides the same |
| pentagon | a shape with 5 sides and 5 angles |
| octogon | a shape with 8 sides and 8 angles |
