Answer:
20 feet
Explanation:
Use the Pythagorean Theorem.
Formula: a^2 + b^2 = c^2
a is the length, and b is the height, and c is the longest edge of the triangle. In this case, you need to find b, the height. Plug in the numbers and solve:
15^2 + b^2 = 25^2
225 + b^2 = 625
-225 -225
b^2 = 400
Take the square root of b to get b by itself, and do the same to the other side of the equation.
The square root of b equals b;
The square root of 400 equals 20.