- #1

- 32

- 0

a1 = (pi - a)/2;

a2 = (pi + a)/2;

theta = a1: a/60: a2;

rho = ones(size(theta));

rho1 = rho*sin(a1)./sin(theta);

polar(theta, rho);

hold on;

polar(theta, rho1)

The above commands will draw a segment of a unit circle which starts from 60[tex]^{o}[/tex] to 120[tex]^{o}[/tex].

I know everything except the line of "rho1 = rho*sin(a1)./sin(theta);" that I don't know why this equation works from 1 --> 0.866 --> 1 and becomes a straight line. Can anyone tell me the reason? Is it related to a similar triangle or inverse proportion?