用matlab在极坐标下绘制一个正方形,设边长为x,任意顶点坐标为(a,b...答:thetaD = angle(a+(b+x)*1i);jAB = b;jBC = a+x;jCD = b+x;jDA = a;[r0,theta0] = rc(thetaA,thetaB,jAB,N);[r1,theta1] = rr(thetaB,thetaC,jBC,N);[r2,theta2] = rc(thetaC,thetaD,jCD,N);if thetaA*thetaD<0 &&abs(thetaA)>pi/2 thetaA = thetaA+2*pi...