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 AB = n, then BC = 2n
Area = (2n)^2  n^2 = 3n^2
P = 4(n) + 2 (2n) = 8n
AP = 3n^2  8n = 60
3n^2  8n  60 = 0
(n  6) (3n + 10) = 0
n = 6 or  3/10 (rejected)
AC^2 = 6(6) + (12)(12)
AC = 13.42
well
Edited on October 15, 2005, 4:19 am
Edited on October 15, 2005, 4:20 am

Posted by Terence
on 20051015 04:18:32 