Answer:
200 square inch
Step-by-step explanation:
Diagonal of a square divides the square into two triangles of equal area.
[tex] \therefore Area \: of \: triangle \\ = \frac{1}{2} \times Area \: of \: square \\ = \frac{1}{2} \times 400 \\ = 200 \: {in}^{2} [/tex]
