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

AD = AB + BD

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 factor a quadratic expression, apply the FOIL method (First, Outside, Inside, Last) in reverse. First, find the two Last terms that will multiply to produce -3 as well and sum (Inside, Outside) to equal -2. For this problem, those two numbers are -3 and 1. Then, plug these into a set of binomials using the square root of the First variable (y²):

y² - 2y - 3
y² + (-3 + 1)y + (-3 x 1)
(y - 3)(y + 1)

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).

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.