CBSE Class 10 Mathematics Standard 2025: question 16
Set in the CBSE Class 10 board exam of 2025, paper 30/1/1, section A, question 16, for 1 mark. Try it first; the hints and our step-by-step solution are below.
Q16 · 1 mark · MCQCircles
In the given figure, PA is a tangent from an external point P to a circle with centre O. If , then is equal to :
- (A)
- (B)
- (C)
- (D)
Figure in the paper: Circle with centre O. AB is a diameter through O (A at top, B at bottom right). PA is a tangent at A from external point P on the left. PO is drawn to O. Angle POB is marked 115°. See it in the official paper.
Source: official question paper from cbse.gov.in (PDF). See it in the full 2025 board paper, set 30/1/1.
Hints
Open one hint at a time and try again before the next.
Hint 1
AB is a straight line. What is ?
Hint 2
The tangent at A is perpendicular to OA. Now use the angle sum of .
Step-by-step solution
Each step shows the marks it earns, as an examiner would award them. Checked by an independent re-solve from the question paper.
AOB is a straight line (a diameter), so [linear pair].
[tangent ⟂ radius at the point of contact].
- 1 mark
In : , so the answer is option (A).
Answer: , option (A)
Where the marks are
- Chooses option (A) (1 mark)
Revise the chapter
- Chapter: Circles (notes, formulas, where marks are lost and every past question)
- Topic: Tangent Perpendicular to Radius Theorem
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The question is transcribed from the official paper; figures are described in words. The solution, hints and chapter tag are ours. Spotted an error? Write tosupport@questionbuddy.in.