X=-2:0.01:6;
y=-2:0.01:2;
S=0;
h=0.01;
x=-2:0.01:6;
y=-2:0.01:2;
s=0;
h=0.01;
for i=1:800
    for j=1:400
        xx=-2+i*h;
        yy=-2+j*h;
        if xx^2+yy^2<=16
            if xx^2/36+yy^2<=1
                if (xx-2)^2+(yy+1)^2<=9
                    s=s+h^2;
                end
            end
        end
    end
end
s
t=0:0.01:2*pi;
x=sin(t);
y=cos(t);
plot(4*x,4*y,6*x,y,2+3*x,3*y-1)
axis([-6,6,-6,6]);