Answer:
12
Explanation:
1. Use the Pythagorean Theorem to solve: a^2+b^2=c^2.
Here you are given the hypotenuse (which is always c in the formula), and one other leg that could be either a or b.
2. Plug these numbers into the formula and evaluate them.
a^2 + 16^2 = 20^2
16 x 16 =256
20 x 20 = 400
So that gives you a^2 + 256 = 400.
3. Subtract 256 from both sides and take the square root of the result.
400 - 256 = 144
a^2 = 144
= 12