class complex (x,y); real x,y; begin real angle, radius; - a radiuS: =sqrt (X**2+y**2) if abs (x) <epsilon then begin if abs(y epsilon then error else begin if y>epsilon then angle: =pi/2 else angle = 3*pi/2 end end else angle: =arctan(y/x) end complexclass complex（x，y）；real x，y； begin real angle，radius； radius：=sqrt（x**2+y**2）； if abs（x）<epsilon then begin if abs(y)<epsilon then error else begin if y>epsilon then angle:=pi/2 else angle:=3*pi/2 end end else angle:=arctan(y/x) end complex