The sine rule is sinA/a=sinB/b=sinC/c. For a=36, c=50 we have sinA/36=sinC/50, so sinA=36sinC/50=18sinC/25. Without sinC this cannot be evaluated and we have no more info. Two sides and no angles doesn't allow us to find any angles or the third side.
If, however, C is a right angle then sinA=18/25=0.72 and A=sin^-1(0.72)=46.05 degrees.