C = 71 degrees
b = about 8.70 (8.7)
c = about 15.43
C: All the angles in a triangle add up to 180 degrees. So, to find "C", you add together "A" and "B" (69 and 40) and subtract their total from 180. This will give you C = 71 degrees.
Now we will solve for "b"and "c". When solving for a side angle, you use the following system; a/SinA = b/SinB = c/SinC.
b: Since we can fill in for a/SinA, and the Sin B b/SinB we will use that to solve for "b". Filling in for each know part, you'll get 15/69 = c/71. Next you multiply 15 and 71, then divide by 69 to get b. 15*71 = 1,065. 1,065/69 = 15.4347... which rounded equals 15.43.
c: Using the same steps as "b", we will now find "c". 15/69 = b/40. Multiply 15 and 40, then divide by 69. 15*40 = 600. 600/69 = 8.6956... which rounded equals 8.70 or 8.7.
I hope this helps!