Question

The area of a parallelogram is 100 in.². Its height is 5 in. What are the lengths of the bases?

Answer 1

Well the formula for the area of a parallelogram is Base * Height. (Proof @ http://en.wikipedia.org/wiki/Parallelogram#Area_formulas)

Now Area is given and Height is given. Therefore you can easily find the base.
100=15*b; find b. :)

Answer 2

so 15 is the answ

Answer 3

Sorry. 100=5*b. so b=100/5. Therefore 20 is the answer.