Answer:
The answer is 16.
Step-by-step explanation:
To solve you need to use Pythagorean Theorem. a^2 + b^2 = c^2 .
12^2 + b^2 = 20^2
144 + b^2 = 400
400 - 144 = 256
b^2 = 256
Next we need to take away the power of 2.
√256 = √b^2
√16 x 16 = √b * b
b = 16
