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.
sin 60 = AB/4 (sin = opposite/hypotenuse)
sqrt3 / 2 = AB/4
4 sqrt3 / 2 = AB
AB= 2 sqrt(3)
or even easier, you could just use the pythagorean theorem: AB=sqrt(4^2-2^2)=sqrt12=2sqrt3