t=-2*pi:0.01:2*pi;x=0.8*cos(t);y=0.8*sin(t);subplot(3,4,6)plot(x,y,'y-')axis([-11-11])axissquarex=1:0.001:2;y1=0.8;y2=0.2;x1=1.5;y3=0.2:0.0001:0.8;subplot(3,4,1)plot(x,y1,'y-',x,y2,'y-',x1,y3,'y-')axis([1201])axissquaresubplot(3,4,5)x4=1.3:0.01:2;x6=1.3;plot(x6,y3,'y-',x4,y2,'y-')axis([1201])axissquarex5=-0.6:0.01:0.6;y5=abs(x5)+0.2;subplot(3,4,7)plot(x5,y5,'y-')axis([-1101])axissquarex6=-pi:0.01:pi/2;y=0.8*cos(x6);x=0.8*sin(x6);X6=-0.8:0.01:0.8;Y6=0;subplot(3,4,8)plot(x,y,'y-',X6,Y6,'y-')axis([-11-11])axissquarex7=-0.8;x8=0.8;y8=0:0.0001:0.8;X7=pi/2:0.01:3*pi/2;y9=0.8*cos(X7);x9=0.8*sin(X7);subplot(3,4,9)plot(x7,y8,'y-',x8,y8,'y-',x9,y9,'y-')axis([-11-11])axissquare