Question 790407
The ratio of the width of a rectangle to its length is 5:2. If its perimeter is 56 cm, what is the measure of its length and width?
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I assume you meant to write rectangle instead of triangle.

let x=width of rectangle
let y=length of rectangle
x/y=5/2
y=2x/5
..
2x+2y=perimeter=56
2x+2(2x/5)=56
2x+4x/5=56
10x+4x=280
14x=280
x=20
y=2x/5=40/5=8
..
width of rectangle=20cm
length of rectangle=8cm