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Question

A circle is inscribed in a right triangle with legs of length 5 and 12. What is the radius of the circle?

This question was previously asked in
SSC CGL 2025 Tier 2 Paper 1 Question Paper (19-Jan-2026)
The correct answer is

2

Step 1 – find the hypotenuse:

\(c = \sqrt{5^2 + 12^2} = \sqrt{25 + 144} = \sqrt{169} = 13\)

Step 2 – use the inradius formula for a right triangle:

For a right triangle with legs \(a,\ b\) and hypotenuse \(c\), the inradius is \(r = \dfrac{a + b - c}{2}\).

\(r = \dfrac{5 + 12 - 13}{2} = \dfrac{4}{2} = 2\)

Hence the radius of the inscribed circle is 2.

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Similar Questions

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Important Questions from Circles, Chords and Tangents

  1. A chord 21 cm long is drawn in a circle of diameter 25 cm. The perpendicular distance of the chord from the centre is:

  2. AB is a chord of a circle with centre O and P is any point on the circle. If ∠APB = 112°, then what is the measure of ∠OAB ?

  3. In a circle with radius 5 cm, a chord is at a distance of 3 cm from the centre. The length of the chord is:

  4. The distance between the centres of two circles is 24 cm. If the radius of the two circles are 4 cm and 8 cm, then what is the sum of the lengths (in cm) of the direct common tangent and the transverse common tangent?

  5. An equilateral triangle ABC and a scalene triangle DBC are inscribed in a circle on same side of the arc. what is ∠BDC equal to?

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