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 entire length of this line is represented by AD which is AB + BD:

AD = AB + BD

The first step to solve a quadratic expression that's not set to zero is to solve the equation so that it is set to zero:

c² + 10c + 3 = c - 5
c² + 10c + 3 + 5 = c
c² + 10c - c + 8 = 0
c² + 9c + 8 = 0

Next, factor the quadratic equation:

c² + 9c + 8 = 0
(c + 1)(c + 8) = 0

For this expression to be true, the left side of the expression must equal zero. Therefore, either (c + 1) or (c + 8) must equal zero:

If (c + 1) = 0, c must equal -1
If (c + 8) = 0, c must equal -8

So the solution is that c = -1 or -8

The surface area of a cylinder is 2πr² + 2πrh:

sa = 2πr² + 2πrh
sa = 2π(6²) + 2π(6 x 6)
sa = 2π(36) + 2π(36)
sa = (2 x 36)π + (2 x 36)π
sa = 72π + 72π
sa = 144π

Parallel lines are lines that share the same slope (steepness) and therefore never intersect. A transversal occurs when a set of parallel lines are crossed by another line. All of the angles formed by a transversal are called interior angles and angles in the same position on different parallel lines equal each other (a° = w°, b° = x°, c° = z°, d° = y°) and are called corresponding angles. Alternate interior angles are equal (a° = z°, b° = y°, c° = w°, d° = x°) and all acute angles (a° = c° = w° = z°) and all obtuse angles (b° = d° = x° = y°) equal each other. Same-side interior angles are supplementary and add up to 180° (e.g. a° + d° = 180°, d° + c° = 180°).