| Complementary angles | Two angles whose measures, when added together, equal 90°. |
| Compound event | An event made up of two or more simple events. |
| Coordinate plane/graph | A two-dimensional system in which the coordinates of a point are its distances from both a horizontal and a vertical line called the axes. The pairs of numbers are called ordered pairs. The first number, called the x-coordinate, designates the distance along the horizontal axis. The second number, called the y-coordinate, designates the distance along the vertical axis. The point at which the two axes intersect has the coordinates (0,0) and is called the origin. |
| Corresponding angles (1) | When a transversal intersects two lines, corresponding angles are on the same side of the transversal and on the same side of the given lines. In the figure below, angles 1 and 2 are corresponding. |
| Corresponding angles (2) | Angles in the same relative position in similar or congruent figures. |
| Mutually exclusive events | Two events that cannot occur at the same time. |
| Net | A two-dimensional shape that can be folded to create a three-dimensional figure. |
| Obtuse triangle | A triangle with one angle that measures more than 90º. |
| Order of operations | Rules describing what sequence to use in evaluating expressions. (1) Perform operations in grouping symbols, (2) Evaluate exponents, (3) Multiply or divide from left to right, (4) Add or subtract from left to right. |
| Perfect square | The product of an integer multiplied by itself (e.g., 121 is a perfect square because 11x11=121). |
| Scatterplot | A graph with points plotted to show a relationship between two variables. |
| Scientific notation | A form of writing very large or very small numbers using a number greater than or equal to 1 and less than 10 multiplied by a power of 10 (e.g., 4.7 x 109 = 4,700,000,000). |
| Stem-and-leaf plot | A data display that shows groups of data arranged by place value. |
| Supplementary angles | Two angles whose measures, when added together, equal 180°. |
| Surface area | The sum of the areas of all of the faces of a three-dimensional figure. |