path a[],aa[];
color cl[];
picture p;
cl1=green;
cl2=blue;
cl3=red;
w=5cm;
r=1cm;
for i=1 upto 3:
 a[i]=fullcircle scaled 2cm;
endfor
x.a1+x.a2=w;
x.a3=w/2;
x.a2-x.a1=r;
z.a3-z.a1=r * (cosd 60, sind 60);
z.a2-z.a3=r * (cosd -60, sind -60);
y.a1+y.a3=w;
for i=1 upto 3:
 aa[i]=a[i] shifted z.a[i];
 fill aa[i] withcolor cl[i];
endfor
for i=1 upto 3:
 j:=i+1; if j=4: j:=1 fi;
 p := image(fill aa[i] withcolor cl[i]+cl[j]);
 clip p to aa[j];
 draw p ;
endfor
clip p to aa2;
draw p withcolor cl1+cl2+cl3;
draw z.a1--z.a2--z.a3--cycle;
endfig;