ratio triangle height to square side 7:8
ratio triangle base to square side 1:2
Area of the square is 64 in² then the sides = 8 in
ratios give
h = 7(8)/8
h = 7
b = 8/2
b = 4
Area Triangle = 0.5(7)(4)
= 14
Then shaded region is the Area of the square minus the Area of the triangle.
A = 64 - 14
A = 50 in²