"What is the area? You should be able to solve this"

[Albert Chan]

(08-07-2018 08:59 AM)Pekis Wrote:  Follow me in my complicated way:
A=16
B=20
C=32
X=?
...
=> A=d/4*(d-a-b)
=> C=d/4*(d+a+b)

It is pretty good.
But, had you spotted A + C is independent of a,b, it will cut down a lot of details.

A + C = d/4*(2d) = d^2/2
B + X = d^2 - (A + C) = d^2/2

A + C = B + X
X = A + C - B = 28 cm^2