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.

To combine like terms, add or subtract the coefficients (the numbers that come before the variables) of terms that have the same variable raised to the same exponent.

5a³ - 3a³ = 2a³

An isosceles triangle has two sides of equal length. An equilateral triangle has three sides of equal length. In a right triangle, two sides meet at a right angle.

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

b² + 11b + 24 = 0
(b + 3)(b + 8) = 0

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

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

So the solution is that b = -3 or -8

A line segment is a portion of a line with a measurable length. The midpoint of a line segment is the point exactly halfway between the endpoints. The midpoint bisects (cuts in half) the line segment.