2016 · Q60
A tangent is drawn from an external point O to a circle of radius 3 units at P such that OP = 4 units. If C is the centre of the circle, then the sine of the angle COP is
Elementary MathematicsCircles
- A4/5
- B3/4
- C3/5
- D1/2
Explanation
OP is tangent at P, so ΔOPC is right-angled at P with OP = 4 and hypotenuse OC = 5. By Pythagoras, CP = 3. Thus sin(∠COP) = CP/OC = 3/5, option C.