In the diagram, PTR is a tangent to the centre O. If angles TON = 108°, Calculate the size of angle PTN
- 132o
-
126o
- 108o
- 102o
The correct answer is: B
Explanation
In the diagram; 108° + x + x = 180° (sum of angle in a triangle)
108° + 2x = 180°
x = 180° - 108°
= 72°
x = \(\frac{72^o}{2}\)
= 36°
(Angle between tangent and a chord through the point of contact)
Hence, angle PTN = 90 + 36
= 126°