Question 869356
the perimeter of a rectangle and square are 160 metre each. the area of rectangle is less than that of square by 100 square metre. find the length of rectangle?
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side of square=160/4=40
area of square=40*40=1600
..
let x=length of rectangle
let y=width of rectangle
2x+2y=160
x+y=80
y=80-x
Area of rectangle=x*y=x(80-x)=80x-x^2
Area of square-area of rectangle=100
1600-(80x-x^2)=100
1600-80x+x^2=100
x^2-80x+1500=0
(x-30)(x-50)=0
x=50
or
x=30
length of rectangle=50 m