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

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