Question

In the given figure, AOB is a diameter and DC is parallel to AB. If  ∠ CAB = x^o ; find (in terms of x) the values of: ∠ DAC

Answer 1

∠DAC = `1 /2 ` ∠DOC = `1/2 (180° - 4x ) = 90° - 2x `

(Angle at the centre is double the angle at the circumference subtended by the same chord)