Fie a=bile mici; b= bile mijlocii; c= bile mari
a+b+c= 180
a=(b+c) :2
b=c-30 =>c = b+30
a ______ +15
b ______
c ______+30
avem 3 segmente egale +30+15
180-(30+15)=180-45 = 135
135:3 = 45 (un segment)
a = 45+15 = 60 (bile mici)
b = 45 (bile mijlocii)
c = 45+30 = 75 (bile mari)
V: 60+45+75=180