Question

Which proportion could be used to find the length of side b?

Answer 1

the correct answer would be D

Answer 2

D sin 85 sin 31

---------- = ----------

b 9.3

Explanation:

We can use the law of sins

sin B sin A sin C

---------- = ----------- = ----------

b a c

We do not know angle C, but we can calculate it

The angles of a triangle add to 180

A + B + C = 180

64+ 85 + C = 180

149 + C = 180

C = 180-149

C =31

sin B sin C

---------- = ----------

b c

We know B = 85, C = 31, b = unknown and c = 9.3

sin 85 sin 31

---------- = ----------

b 9.3