math
posted by Please help 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 square inches , and one base 12 inches long, what is the length, in inches, of its other base?

A = h( b1+b2)/2
not over 5 I think
No need to think. Just write the equation down and plug in the numbers:
55 = 5 (12+b2)/2
22 = 12+b2
b2 = 10