| A | B |
|---|
| angle | Formed by 2 rays with a common endpoint |
| acute angle | measures less than 90° |
| right angle | measures 90° |
| obtuse angle | measures between 90° and 180° |
| straight angle | measures 180° |
| complementary angles | add up to 90° |
| supplementary angles | add up to 180° |
| congruent angles | have the same measure |
| parallel lines | lines in a plane that never meet |
| right angles | Formed by perpendicular lines, rays and segments |
| rhombus | Quadrilateral with all sides congruent. |
| trapezoid | quadrilateral with 1 pair of parallel sides |
| Angles of a triangle total | 180° |
| Angles of a quadrilateral total | 360° |
| regular polygons | Sides and angles congruent |
| Area of a rectangle | base (length) x height (width): A = bh |
| perimeter of a figure | Distance around perimeter's edge |
| perfect square | Square of a whole number |
| square root of a number | length of the side of square whose area is that number |
| Hypotenuse of a right triangle | Side opposite the right angle. Other sides called the legs. |
| Pythagorean Theorem | Says: sum of squares of lengths of legs of a right triangle = square of length of hypotenuse |
| triangle's area | Half the product of the triangle's base length + height: A = 1/2bh |
| area of parallelogram | product of length of base + height: A = bh |
| area of trapezoid | half length x sum of lengths of bases: A = 1/2h(b1 + b2) |
