Jack uses 64 inches of wood to build a rectangular picture frame. the length of one side is 25 inches. what is the length of the other side? what do you need to find to solve the problem? choose the word that completes the sentence. area, perimeter, or side length

Well, a rectangle has 4 sides and the opposite side is at an equal length so you want to do 25 in. times 2= 50 inches. Then you want to subtract the 50 inched from 64 inches which will equal = 14. Then to get the other side lengths you need to divide it my two which is 7. 
So your side lengths are seven inches. The word is side lengths. 

You would do 64 - 25 = 39. To check you can do 39 + 25 = 64. To find the perimeter you do length + width.