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

AD = AB + BD

You need to find the value of b so solve the first equation in terms of y:

8b + y = -6
y = -6 - 8b

then substitute the result (-6 - 8b) into the second equation:

8b - 3(-6 - 8b) = 9
8b + (-3 x -6) + (-3 x -8b) = 9
8b + 18 + 24b = 9
8b + 24b = 9 - 18
32b = -9
b = \( \frac{-9}{32} \)
b = -\(\frac{9}{32}\)

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(9 + 3)(4)
a = ½(12)(4)
a = ½(48) = \( \frac{48}{2} \)
a = 24

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 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.