3:5:7=180 degrees 15=180 15 divided by15=180 divided by 15 so, 1=12
so= 3:5:7 equal to (3*12) (5*12) (7*12)
A,B,C angles measures respectively = 36:60:84 if you add them (A,B,C angles) we can obtain = 36:60:84=180 (sum of the measures of the angles of a triangle is 180 degrees)