Question

In △ABC, m∠B = 45, a = 24 ft, and c = 30 ft. Find b. Round your answer to the nearest tenth.

Answer 1

To get the value of b we use the cosine rule:
c²=a²+b²-2ab Cos C
in our situation the formula will be:
b²=a²+c²-2ac Cos B
thus plugging our values we shall have:
b²=24²+30²-2×24×30×Cos45
b²=457.76624
b=21.3955~21.4 ft
Answer: 21.4 ft