In order to solve this, we need to use the rule of sine which is (a/sinA)=(b/sinB)=(c/sinC). Since we have both values of c we can do (12/sin104), which equals ~12.37. Therefore, since we already have A, 12.37=(a/sin40). We can change this by doing sin40×12.37=a. sin40×12.37=7.95.
