Acity is building a fence around a rectangular playground. if the perimeter of the playground is 90 feet and the length of one side of the fence is 28 feet, what is the width of the playground?

90=l+l+w+w
90=28+28+w+w
90=56+2w
34=2w
17=w
The width of the playground is 17.

A rectangle has 2 lengths of the same and 2 widths of the same. so your length is 28(56 for both sides) and subtraact it from 90 wich is yoru total perimite you get 34 and now devide by 2 and your widths will be 17 for both. 

It would be 15 m how i got the answer: (20x20) + b^2 = (25x25)400 + b^2 = 625625-400=225square that and get 15hope this : )