#15

In order to solve triangles it is best to draw a simple equilateral triangle. Label the angles of the triangle A, B, and C labeling clockwise starting where ever. The opposite side of the angle will be the corresponding side to the angle A with a, B with b and so on. For this specific problem c is 14 and a is 10. We also know that angle B will be 130 degrees. In order to find the last remaining side, use the law of cosines and solve for c. Now we can solve for andle a, using the law of cosines. After finding this angle we can add it to the given angle and subtract the resulting sum from 180; calculating angle C.