notam a,b,c,d masurile celor 4 unghiuri
a+b+c+d=360°
0,(3)=3/9=1/3; 0,25=1/4; 0,125=1/8; 0,(1)=1/9
{a,b,c,d} i.p. {1/3; 1/4; 1/8; 1/9}
a/3=b/4=c/8=d/9=k
a=3k; b=4k; c=8k; d=9k
3k+4k+8k+9k=360°
24k=360°
k=15°
a=3•15=45°
b=4•15=60°
c=8•15=120°
d=9•15=135°