Questions | 5 |

Topics | Calculations, Coordinate Grid, Cylinders, Inequalities, Slope-Intercept Equation |

The **circumference** of a circle is the distance around its perimeter and equals π (approx. 3.14159) x diameter: c = π d. The **area** of a circle is π x (radius)^{2} : a = π r^{2}.

The coordinate grid is composed of a horizontal **x-axis** and a vertical **y-axis**. The center of the grid, where the x-axis and y-axis meet, is called the **origin**.

A cylinder is a solid figure with straight parallel sides and a circular or oval cross section with a radius (r) and a height (h). The **volume** of a cylinder is π r^{2}h and the **surface area** is 2(π r^{2}) + 2π rh.

Solving equations with an inequality (<, >) uses the same process as solving equations with an equal sign. Isolate the variable that you're solving for on one wide of the equation and put everything else on the other side. The only difference is that your answer will be expressed as an inequality (x > 5) and not as an equality (x = 5).

A line on the coordinate grid can be defined by a slope-intercept equation: **y = mx + b**. For a given value of x, the value of y can be determined given the **slope** (m) and **y-intercept** (b) of the line. The slope of a line is change in y over change in x, \({\Delta y \over \Delta x}\), and the y-intercept is the y-coordinate where the line crosses the vertical y-axis.