Answer: 28.3 inches long
Explanation:
Since the triangle is isosceles, the two legs have the same length. Let's call the length of each leg "x". We can use the Pythagorean theorem to solve for x:
x^2 + x^2 = 40^2
2x^2 = 1600
x^2 = 800
x ≈ 28.3
Therefore, each leg of the triangle is approximately 28.3 inches long.