algebra1
posted by Maram on .
The area of trapezoid is h( b1+b2)/5,
where h is the altitude, and b1 and b2 are the lenghts of the parallel bases. If trapezoid has an altitude of 5 inches, an area of 55 sguare inches , and one base 12 inches long, what is the lenghth, in inches, of its other base?

A = (b1+b2)h/2 = 55in^2.
(b1+12)5/2 = 55,
Multiply both sides by 2:
(b1+12)5 = 110,
5b1+60 = 110,
5b1 = 11060 = 50,
b1 = 10 in.