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.

The Pythagorean theorem defines the relationship between the side lengths of a right triangle. The length of the hypotenuse squared (c²) is equal to the sum of the two perpendicular sides squared (a² + b²): c² = a² + b² or, solved for c, \(c = \sqrt{a + b}\)

The volume of a cylinder is πr²h:

v = πr²h
v = π(2² x 4)
v = 16π

A triangle is a three-sided polygon. It has three interior angles that add up to 180° (a + b + c = 180°). An exterior angle of a triangle is equal to the sum of the two interior angles that are opposite (d = b + c). The perimeter of a triangle is equal to the sum of the lengths of its three sides, the height of a triangle is equal to the length from the base to the opposite vertex (angle) and the area equals one-half triangle base x height: a = ½ base x height.

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

x² - x - 30 = 0
(x + 5)(x - 6) = 0

For this expression to be true, the left side of the expression must equal zero. Therefore, either (x + 5) or (x - 6) must equal zero:

If (x + 5) = 0, x must equal -5
If (x - 6) = 0, x must equal 6

So the solution is that x = -5 or 6