Question

Calculate the size of θ in the given diagram ( see image).
O is the center of the circle.​

Answer 1

• 42°

Explanation:

• The triangle is isosceles as two sides are radius.
• The central angle and the tangent chord angle refer to same arc.
• Tangent chord angle is half the size of the central angle.

The central angle is:

• 2*48° = 96°

The other angles in the triangle are equal:

• ∠θ = 1/2(180° - 96°) = 1.2(84°) = 42°