View difference between Paste ID: H7B6kABM and wHEBGUML

 import geometry;
 
 size(9cm, 0);
 defaultpen(fontsize(10pt));
 dotfactor = 4;
 
-pair A,B,B1,C;
+point A,B,B1,O,C;
-point O=origin;
+
-real r = 2;
+B=(0,0); B1=-2*dir(80);
-real x = 5/21;
+circle circ = circle(B, B1);
-circle circ = circle(O, r);
+
-B= point(circ, x*length(circ));
+
-B1= point(circ, (x+1/2)*length(circ));
+A=point(circ, B-1/4*length(circ)); //не смог придумать решени, как от точки B отступить дугу 90
 
 fill(A--O--B--cycle, red+white);
-A=point(circ, (x+1/4)*length(circ) );
+
 fill(A--O--C--B1--cycle, orange+white);
 
 markangle(Label("$\alpha$", Relative(0.5), align = NE), radius = 0.3cm, n=1, C,O,B);
-fill(arc(O,B1,C)--O--cycle, orange+white);
+
-fill(arc(O,A,B1)--O--cycle, orange+white);
+
 draw(B--C^^O--C^^O--A^^A--B);
 draw(circ);
 
 
 pair   p []={A, B, B1, C, O};
 pair   v []={W, N, S, SE, SW};
 string n []={"$A$", "$B$", "$B_1$", "$C$", "$O$"};
 
 for ( int k=0; k<p.length ; ++k)
 dot ( Label (n[k] , align =v[k]) ,p[k ]);
 
 label(Label("$1$", Relative(0.5)), A--O);
 label(Label("$1$", Relative(0.5)), B--O);
 label(Label("$1$", Relative(0.5)), C--O);
 label(Label("$\sqrt2$", Relative(0.5), Rotate(dir(A--B)), align = N), A--B);
 label(Label("$\frac{10}3$", Relative(0.5), Rotate(dir(B--C)), align = NE), B--C);
 label("$S_1$", (A+O+B)/3);
 label("$S_2$", (C+O+B)/3);
 label("$S_3$", (3*A+3*O+C)/6);