Prove that the angle between the tangent and the chord (p) is equal to the angle in the alternate segment (q).
Hint: The line AC goes through the centre O so this is a straight line. Angle in a semi-circle?
Angle AOC is 180°,
angle ABC is angle in a semi-circle = 90°
Also the tangent at A is 90° to line AC
So BAC = 90° – p
Angle q must be equal to p
Hence p = q
Find the value of P: