Answer:
32.7°
Explanation:
Use the formula for law of cosines, for this question we need so solve for angle B, so use...
b² = a² + c² - 2(a)(c)Cos B
We are given a, b, and c, so plug them in...
55² = 90² + 50² - 2(90)(50)Cos B
Now simplify...
3,025 = 8100 + 2500 - (9000)Cos B
-7,575 = -(9000)Cos B (subtract 8100 and 2500 from both sides)
0.841666667 = Cos B (divide both sides by -9000)
Cos^(-1) 0.841666667 = B (use cosine inverse function on calculator)