NCERT Exemplar Solutions
Class 10 - Mathematics - CHAPTER 9: Circles - Exercise 9.2
Question 6

Question. 6

If the angle between two tangents drawn from a point \(P\) to a circle of radius \(a\) and centre \(O\) is \(60^\circ\), then \(OP = a\sqrt{3}\). State True/False and justify.

Answer:

False.

Detailed Answer with Explanation:

Step 1: Let the angle between the tangents be \(\theta = 60^\circ\).

Step 2: Formula for the distance of the external point \(P\) from the centre \(O\) is:

\( OP = \dfrac{a}{\sin(\theta/2)} \)

where \(a\) is the radius of the circle.

Step 3: Substitute the values:

\( OP = \dfrac{a}{\sin(60^\circ / 2)} = \dfrac{a}{\sin 30^\circ} \)

Step 4: We know \(\sin 30^\circ = 1/2\).

So, \( OP = \dfrac{a}{1/2} = 2a \).

Step 5: The given statement says \( OP = a\sqrt{3} \), but our calculation gives \( OP = 2a \).

Final Answer: The statement is False.

NCERT Exemplar Solutions Class 10 – Mathematics – CHAPTER 9: Circles – Exercise 9.2 | Detailed Answers