Pythagorean Theorem Formula: a^2 + b^2 = c^2
We are solving for b of the triangle.
Steps to solve:
10^2 + b^2 = 15^2
~Solve for the exponents
100 + b^2 = 225
~Subtract 100 to both sides
100 - 100 + b^2 = 225 - 100
~Simplify
b^2 = 125
~Take the square root of both sides
√b^2 = √125
~Simplify
b = 11.1803398875
~Round to the nearest tenth
11.1803398875 → 11.2
Hence, the length of "b" is 11.2
Best of Luck!