A = (0, 0)
B = (1, 0)
C = Point(xAxis)
c = Semicircle(C, B)
D, E = Intersect(c, yAxis)
b = Segment(A, D)
a = Segment(A, C)
Vieleck1, c_1, b_1, d = Polygon(B, D, C)
e = Segment(A, B)
Text1: "\sqrt {" + a + "}\quad \approx \quad " + b