In triangle ABC, AB = 20 feet, BC = 15 feet, and measure angle B = 124 degrees. What is the length of AC? Round your answer to your nearest tenth.
Using the law of cosines, we can find the length of AC:
AC^2 = AB^2 + BC^2 - 2(AB)(BC)cos(B)
AC^2 = 20^2 + 15^2 - 2(20)(15)cos(124)
AC^2 = 400 + 225 - 600(-0.588)
AC^2 = 625 + 352.8
AC^2 = 977.8
AC ≈ 31.3 feet
Therefore, the length of AC is approximately 31.3 feet.