To multiply binomials, use the FOIL method. FOIL stands for First, Outside, Inside, Last and refers to the position of each term in the parentheses.

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

z² - 12z + 32 = 0
(z - 4)(z - 8) = 0

For this expression to be true, the left side of the expression must equal zero. Therefore, either (z - 4) or (z - 8) must equal zero:

If (z - 4) = 0, z must equal 4
If (z - 8) = 0, z must equal 8

So the solution is that z = 4 or 8

A right angle measures 90 degrees and is the intersection of two perpendicular lines. In diagrams, a right angle is indicated by a small box completing a square with the perpendicular lines.

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 formula for circumference is circle diameter x π:

c = πd
c = 11π