jmc

Question

In right triangle ABC, the length of side BC is 2 units, the length of side AC is 4 units and the measure of angle C is 60 degrees. What is the length of side AB, in units? Express your answer in simplest radical form.

Accepted Answer

The right angle is either A or B. It can't be A since it must be opposite the longest side, and BC<AC, so B is a right angle. By the Pythagorean Theorem, AB^2+BC^2=AC^2, or AB^2=16-4=12 and AB=12=23.