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 area of a trapezoid is one-half the sum of the lengths of the parallel sides multiplied by the height:

a = ½(b + d)(h)
a = ½(5 + 8)(5)
a = ½(13)(5)
a = ½(65) = \( \frac{65}{2} \)
a = 32\(\frac{1}{2}\)

To multiply monomials, multiply the coefficients (the numbers that come before the variables) of each term, add the exponents of like variables, and multiply the different variables together.

(7a)(9ab) - (7a²)(3b)
(7 x 9)(a x a x b) - (7 x 3)(a² x b)
(63)(a¹⁺¹ x b) - (21)(a²b)
63a²b - 21a²b
42a²b

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).

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:

(y + 4)(y - 7)
(y x y) + (y x -7) + (4 x y) + (4 x -7)
y² - 7y + 4y - 28
y² - 3y - 28