Answer:
Line passing through
.
Step-by-step explanation:

hence this line passes through
.
When 

Hence this line passes through
.
Graph is attached.
One side of Square A is the hypotenuse of the white triangle. The square of this hypo. is 24^2+10^2 = 576 + 100 = 676. Since the square of the hypo is the area of Square A, Square A has the area 676 sq. in.
Well, it's 10/45, or 2/9, or 22.22%, or whatever :))