Answer:
15 inches
Step-by-step explanation:
1. Use the Pythagorean Theorem: a^2+b^2=c^2
You are already given c (the longest side) and one of the legs which could be a or b.
2. Plug the numbers into the formula and square them.
a^2 + 36^2 = 39^2
Squaring the numbers gives you: a^2 + 1,296 = 1,521
3. Subtract 1,296 from both sides and take the square root of the result.
a^2 = 225
= 15