Tasneem Raslan: There's a question that I'm confused about, and I'd really appreciate some help. There's a circle, and two radii that extend to form a chord AB. The minor angle is given as 2O rads, and the question is to find the an expression for the chord in terms of r (radius) and O. I need to find the chord using the sine rule, but no matter what I do, my answer doesn't match the mark scheme. If you ask, I did sin2O/(AB) = sin((π-2O)/2)/r. The mark scheme says the answer is 2rsinO, but my answer includes π. Thanks in advance.