Suppose the sun casts a shadow off a 35-foot buliding. If the angle of elevation to the sun is 60 degrees, how long is the shadow to the nearest tenth of a foot?

If you draw the figure, you will realize that the building, shadow and the sunrays will form a 30-60-90 triangle. Remember that in a 30-60-90 triangle, the side opposite to 60 is root3 times the side opposite 30.
Thus 35=root3 * shadow. So shadow is 35/root3 = 35/1.732 = 20.2 feet.