Good. Now you also need to know some basic angles. All three angles in an equilateral triangle have measure radians. If you drop a perpendicular from one vertex to the opposite side, you divide the triangle into two congruent right triangle with angles of and [/tex]\pi/6[/tex]. If you take the equilateral triangle to have sides of length 1, the hypotenuse of the right triangles is 1 and the leg opposite the angle is 1/2.