Look at this shape:

Assume AB = AF = FE = ED and BC = CD, and all the angles in the shape are 90 degrees.

Let A be the area of this shape (in cm^2), and P -- the perimeter of this shape (in cm).

If A - P is 60, what is the length of line AC?

let cd =x then ab,af,fe,ed=x/2 and bc=x
area of fig =(x^2)-1/4(x^2)=3x^2/4
perimeter =4x
thus 3x^2-16x=60*4
therefore x=56.
also adc is an equilateral triangle threfore ac=56

Posted by bharath on 2003-10-11 14:24:19