Question

1. geometry formula (lesson 1.5)

the area (a) of a trapezoid is given by the formula a = \frac{1}{2}h(b1 + b2). which formula gives b1 in terms of a, h, and b2?
a) b1 = 2ha - b2
b) b1 = h2a - b2
c) b1 = h2a + b2
d) b1 = 2ah - b2

Explanation:

Step1: Multiply both sides by 2

$2A = h(b1 + b2)$

Step2: Divide both sides by h

$\frac{2A}{h}=b1 + b2$

Step3: Isolate b1

$b1=\frac{2A}{h}-b2$

Answer:

D. b1 = 2A/h - b2