### Home > INT3 > Chapter 12 > Lesson 12.2.2 > Problem12-93

12-93.

If the side lengths of $ΔABC$ are $BC = 9, AC = 10$, and $AB = 5$, calculate the measure of the largest angle.

The largest angle is opposite the longest side.

Use the Law of Cosines.

$m∠B\approx86.17^\circ$