| A | B |
|---|
| obtuse angle | angle larger than 90 degrees |
| right angle | angle that equals 90 degrees |
| intersecting lines | lines that cross each other |
| line segment | part of a line with 2 endpoints |
| polygon | a closed figure with straight sides |
| triangle | a polygon with 3 sides and 3 angles |
| pentagon | a polygon with 5 sides and 5 angles |
| radius | the distance from the center of a circle to the edge of a circle |
| circumference | the length of a line which travels from one edge to another, going through the center |
| rotation | turn |
| reflection | flip |
| translation | slide |
| square | a quadrilateral with right angles and 4 equal sides |
| rhombus | a quadrilateral with 2 sets of parallel lines and all sides are equal |
| parallelogram | a quadrilateral with 2 sets of parallel lines; opposite sides are equal |
| acute angle | angle smaller than 90 degrees |
| perpendicular lines | lines that intersect and from right angles |
| parallel lines | lines that are always the same distance apart and never cross |
| quadrilateral | a polygon with 4 sides and 4 angles |
| hexagon | a polygon with 6 sides and 6 angles |
| octagon | a polygon with 8 sides and 8 angles |
| rectangle | a quadrilateral with 4 right angles and with opposite sides that are equal |
| trapezoid | a quadrilateral with one set of parallel lines |
| area | the amount of space an object takes up |
| perimeter | the distance around an object |
