| A | B |
|---|
| point | an exact location in space |
| line | a collection of points along a straight path |
| line segment | a part of a line having two endpoints |
| ray | a part of a line having only one endpoint |
| angle | two rays having a common endpoint |
| plan | an endlesss flat surface |
| acute angle | an angle measuring less than 90˚ |
| obtuse angle | an angle measuring more than 90˚ |
| straight angle | an angle measuring exactly 180˚ |
| right angle | an angle measuring exactly 90˚ |
| vertex | a point whre 2 rays meet |
| intersecting lines | two lines that meet at a point |
| parallel lines | two lines in the same plane that never intersect |
| perpendicular lines | two lines that meet to form right angles |
| triangle | a 3 sided figure |
| quadrilateral | a 4 sided figure |
| polygon | a closed plane figure made up of line segments |
| pentagon | a 5 sided figure |
| hexagon | a 6 sided figure |
| octagon | an 8 sided figure |
| decagon | a 10 sided figure |
| congruent | figures that are the same shape and the same size |
| corresponding parts | matching parts of congruent figures |
| symmetry | a figure is this when it can be folded so that both sides match |
| similar | figures that have the same shape(not the same size) |
| equilateral triangle | 3 sides equal |
| isosceles triangle | 2 sides equal |
| scalene triangle | NO sides equal |
| acute triangle | 3 acute angles |
| obtuse triangle | 1 obtuse angle |
| right triangle | 1 right angle |
| quadrilateral | a shape that has four sides and four angles |
| trapezoid | there are exactly one pair of opposite sides parallel |
| parallelogram | each pair of opposite sides are paralled and opposite sides and agles are congruent |
| rhombus | a parallelogram with all sides congruent |
| rectangle | a parallelogram with four right angles |
| square | a rectangle with four congruent sides |
| circle | a closed plane figure and every point on a circle is the same distance from the center |
| diameter | a segment that passes through the center of a circle and has both endpoints on the circle |
| radius | a segment with one endpoint on the circle and one endpoint at the center |
| chord | a segment with both endpoints on the circle |
| arc | a part of a circle |
| semicircle | an arc that is one half of a circle |
| compass | an instrument used to draw a circle |
