Students are taught the "unit circle" and its relationship to trigonometry ... Sign up An icon in the shape of an angle pointing down. Jump to ...

Save guides, add subjects and pick up where you left off with your BBC account. More simply, the angle at the centre is double the angle at the circumference. Angle OGH (\(y\)) = angle OHG because ...

therefore this forms an isosceles triangle inside the circle. Also, note that since triangle AOB is isosceles, then \(\angle OAB=\angle OBA\). \(\angle AOC\) is a straight angle, so will add up to ...