Krishnamurthy
An isosceles right triangle has a hypotenuse of h = 18√2 inches.
2x^2 = h^2 = 2*18^2
The area of the isosceles triangle is (1/2)(18)(18) = 162 inches^2
Daniel H
2x^2 = h^2 = (18√2)^2 = 648
x^2 = 324
x = 18
area = 1/2 * base * height
base = height = 18
area = 1/2 * 18 * 18 = 162