A circle is a figure in which each point around its perimeter is an equal distance from the center. The radius of a circle is the distance between the center and any point along its perimeter. A chord is a line segment that connects any two points along its perimeter. The diameter of a circle is the length of a chord that passes through the center of the circle and equals twice the circle's radius (2r).

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 r².

The first step to solve a quadratic equation that's set to zero is to factor the quadratic equation:

a² - 5a - 24 = 0
(a + 3)(a - 8) = 0

For this expression to be true, the left side of the expression must equal zero. Therefore, either (a + 3) or (a - 8) must equal zero:

If (a + 3) = 0, a must equal -3
If (a - 8) = 0, a must equal 8

So the solution is that a = -3 or 8

A cube is a rectangular solid box with a height (h), length (l), and width (w). The volume is h x l x w and the surface area is 2lw x 2wh + 2lh.

The volume of a cylinder is πr²h:

v = πr²h
v = π(2² x 1)
v = 4π