Question

Use the Law of Sines to find the missing angle of the triangle. Find m<b to the nearest tenth.
A) 110.0 degrees
B) 153.9 degrees
C) 26.1 degrees
D) 70.0 degrees

Answer 1

1. By the Law of Sines, you have:

 SinA/a=SinB/b=SinC/c

  2. You don't need the fraction SinC/c, so you can eliminate it. Then:

 SinA/a=SinB/b

 A=40°
 a=19
 B=m∠b
 b=13

 3. When you substitute this values into SinA/a=SinB/b, you obtain:

 SinA/a=SinB/b
 Sin(40°)/19=SinB/13
 SinB=13xSin(40°)/19
 m∠b=SinB^-1(13xSin(40°)/19)
 m∠b=26.1°

 Therefore, the answer is: 26.1 degrees.