| A | B |
|---|
| right angle | A square corner, measures 90º |
| equilateral triangle | A triangle with 3 equal sides. |
| scalene triangle | A triangle having no equal sides |
| vertex | A corner |
| right triangle | A triangle with one right angle |
| pentagon | A polygon with 5 sides and 5 angles. |
| square | A quadrilateral with 4 right angles and four equal side |
| intersecting lines | Lines that cross |
| perpendicular lines | Two lines that cross and form right angles |
| acute angle | A sharp corner, measures less than 90º |
| chord | A line segment with its endpoints on a circle |
| radius | A line segment from the center to the edge of the circle |
| line segment | A piece of a line |
| Line | A straight path that goes forever in opposite directions |
| point | A location in space |
| rectangle | A quadrilateral with 4 right angles |
| circle | The set of all points a fixed distance from a given point |
| hexagon | A six sided polygon |
| obtuse angle | A wide open angle, measures between 90º and 180º |
| ray | Part of a line with one endpoint, that goes forever in one direction |
| angle | Figure formed by two rays with the same endpoint |
| plane | A flat surface that goes forever |
| parallel lines | lines that never cross and are always the same distance apart |
| skew lines | Lines that never cross and are not parallel |
| straight angle | Forms a straight line, measures 180º |
| adjacent angles | Angles right next to each othr, sharing a side |
| congruent | exactly the same size and shape |
| isosceles triangle | Triangle with 2 equal sides |
| acute triangle | Triangle with 3 acute angles |
| trapezoid | Quadrilateral with just one set of parallel sides |
| parallelogram | Quadrilateral with 2 sets of parallel sides |
| rhombus | Quadrilateral with 4 equal sides |
| polygon | A closed figure with straight sides |
| triangle | a polygon with 3 sides |
| quadrilateral | A polygon with 4 sides |
| pentagon | A polygon with 5 sides |
| heptagon | A polygon with 7 sides |
| octagon | A polygon with 8 sides |
| nonagon | A polygon with 9 sides |
| decagon | A polygon with 10 sides |
| regular polygon | A polygon with equal sides and equal angles |
| diagonal | A line segment from one vertex to another |
| similar | Has the same shape but not the same size |
| line symmetry | A line divides a figure into two congruent parts that match when folded |
| rotational symmetry | A shape can be turned less than 360º an match the original |
| translation | Sliding a figure along a line |
| rotation | Turning a figure around a point |
| reflection | Flipping a figure over a line |
| solid figure | A 3-dimensional figure |
| polyhedron | A solid figure with polygon sides |
| face | A polygon used to forme the flat surfaces of a polyhedron |
| edge | Where 2 faces of a polyhedron meet |
| base | The bottom face of a solid figure |
| pyramid | A polyhedron with a polygon base and triangular sides |
| prism | A polyhedron with 2 congruent polygon bases (top and bottom) and rectangular sides |
| surface area | The total areal of all surfaces of a solid figure |
| volume | The amount of space inside a solid figure |
| diameter | A line segment across a circle that passes through the center |
| arc | A piece of the edge of a circle |
| semicircle | Half of a circle |
| circumference | The distance around a circle |
| tangent | A line that touches a circle at just one point |
| π | 3.14 |
