Question

O is the centre of the circle shown below.

Line DHG is a tangent to the circle.

Work out the size of angle a. Justify your answer.​

Answer 1

`\angle EHF=90^(\circ)` (an angle inscribed in a semicircle is a right angle)

`\angle HEF=38^(\circ)` (alternate segment theorem)

`a=52^(\circ)` (angles in a triangle add to 180 degrees)