To solve this for c, you need to use the Law of Sines which is SinA/a=SinB/b=SinC/c. So, your equation would be Sin39/15=Sin79/c. To solve this you would do the fish method. So first, you multiply sin79 x 15. Then you would divide the answer of that by sin(39) which = c
c= 23.4
Hope this helped :)
