Question

1. jeff is building a tabletop in the shape of a trapezoid. the area of the tabletop is to be 21 square feet. the longer base is 7 feet and the height is 3.5 feet. use the formula for the area of a trapezoid, a = \frac{1}{2}h(b_1 + b_2), to find the length of the shorter base.

answer: ________

Explanation:

Step1: Substitute values into formula

$21=\frac{1}{2}\times3.5\times(7 + b_2)$

Step2: Simplify the equation

$21 = 1.75\times(7 + b_2)$

Step3: Solve for $b_2$

$b_2=\frac{21}{1.75}-7=5$

Answer:

5 feet