Lesson 4.5: The Cosine Law m + Deni would like to estimate the height of a hill from its base. Using a compass she found that the angle between C and B, from A, was 80. She also estimated the angle from horizontal to the summit to be 23. She then walked 400 m to B where she measured the angle between A and C to be 610. Use her information to determine the height of the hill. D summit C inaccessible point directly below summit 400 m