Cosine rules.
Find the side of a regular dodecagon that is inscribed in a circle with radius 4 cm. (A regular dodecagon has 12 equal angles and 12 equal sides.) Show your method of solution. You may use geometric vector.
Heights and distances.
The angle of depression to one side of a lake, measured from the passenger cage of a hot air balloon is 43 degrees. The angle of depression measured to the other side of the lake is 27 degrees. The passenger cage of the balloon is 2500 feet above the lake. Find the width of the lake.