58 degrees
Explanation
If you have a triangle with the angle measures of abc as 58 degrees, 102 degrees and 20 degrees you can multiply them in order of abc so 58 degrees is angle a, 102 degrees is angle b and 20 degrees is angle c. Then you just put in angle a for d which would be 58 degrees and angle e for b 102 degrees and angle f for c which would be 20 degrees