CBSE Class 10 Mathematics Basic 2023: question 24
Set in the CBSE Class 10 board exam of 2023, paper 430/4/1, section B, question 24, for 2 marks. Try it first; the hints and our step-by-step solution are below.
Q24 · 2 marks · Very short answerCircles
In the adjoining figure, PT is a tangent at T to the circle with centre O. If , find the value of .
Figure in the paper: A circle with centre O. P is a point outside the circle, and PT is a tangent touching the circle at T. OT is a radius and OP is joined. The angle TPO = 30° is marked at P. The angle x is marked at the centre O, below the line OP. See it in the official paper.
Source: official question paper from cbse.gov.in (PDF). See it in the full 2023 board paper, set 430/4/1.
Hints
Open one hint at a time and try again before the next.
Hint 1
What is the angle between a tangent and the radius at the point of contact?
Hint 2
Find using the angle sum of , then use the straight line through T and O.
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.
- 1 mark
[tangent ⟂ radius at the point of contact]
- 1 mark
In : . Since TO produced is a straight line, [linear pair]
Answer: x = 120°
Where the marks are
- Uses (tangent ⟂ radius) (1 mark)
- Finds and by linear pair (1 mark)
Revise the chapter
- Chapter: Circles (notes, formulas, where marks are lost and every past question)
- Topic: Tangent Perpendicular to Radius Theorem
More questions from Circles
- 2023 board paper, set 430/4/1 (Basic), Q19 · 1 markAssertion (A): A tangent to a circle is perpendicular to the radius through the point of contact. Reason (R): …
- 2023 board paper, set 430/4/1 (Basic), Q31(A) · 3 marksProve that the lengths of tangents drawn from an external point to a circle are equal.
- 2023 board paper, set 430/4/1 (Basic), Q31(B) · 3 marksTwo concentric circles with centre O are of radii 3 cm and 5 cm. Find the length of chord AB of the larger cir…
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.