Use the Law of Cosines to determine the indicated side x. (Assume a = b = 20. Round your answer to one decimal place.)
x =

Answer:
37.6
Step-by-step explanation:
x² = a² + b² - 2ab cos 140°
x² = 20² + 20² - 2(20)(20)(-0.766)
x² = 400 + 400 - 800(-0,766)
x² = 800 - (-612.835)
x² = 800 + 612.835
x² = 1412.835
x =√1412.835 = 37.6