This is the last question on my pre-calc homework, I looked through the textbook and have no idea how to do this.

Use the Law of Sines to solve for all possible triangles that satisfy the given conditions. (If an answer does not exist, enter DNE. Round your answers to one decimal place. Below, enter your answers so that ∠B1 is smaller than ∠B2.)

a = 76 b = 108 ∠A = 21°

∠B1 = °

∠B2 = °

∠C1 = °

∠C2 = °

c1 =

c2 =

1 answer

sinB/b = sinA/a
so,

sinB = 108*sin21°/76 = 0.50925
so, B = 30.6° or 149.4°

Since A+B+C = 180, that means

C is 128.4° or 9.6°
So, since

c/sinC = a/sinA

there are two choices for c, as well.