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Question

A triangular board has sides 9 cm, 10 cm, and 17 cm. A circle passes through all three vertices. Find the circumradius.

This question was previously asked in
UPTET 2026 Paper 2 Social Studies Question Paper (3-Jul-2026) (Shift 1)
The correct answer is

10.625 cm

Using Heron's formula, the semi-perimeter is \(s = \frac{9 + 10 + 17}{2} = 18\).

The area is \(\text{Area} = \sqrt{18 \times 9 \times 8 \times 1} = \sqrt{1296} = 36\) square cm.

The circumradius formula is \(R = \frac{a \times b \times c}{4 \times \text{Area}}\).

Substituting the values gives \(R = \frac{9 \times 10 \times 17}{4 \times 36} = \frac{1530}{144} = 10.625\) cm.

Hence, the circumradius of the triangle is 10.625 cm.

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Similar Questions

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Important Questions from Geometry

  1. If the angles of a triangle are in the ratio of 2:3:4, then the difference of the measure of greatest angle and smallest angle is

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  3. How many lines of symmetry does a rectangle have?

  4. The number of diagonals in each face a cube is

  5. Which of the following is/are the geometric figures with the line of symmetry?

    I. Rectangle

    II. Isosceles triangle

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