Question

The diagonal of a square is 15 inches. find the area of the square

Answer 1

Think of the square as a rhombus:
$\frac{15 \times 15}{2} = \frac{225}{2} = 225 \div 2 = 112.5$
so 112.5 square inches


you can ask if it wasn't clear enough, I will explain.
Have a nice day!!!!