Multiple choice

A circle is inscribed in a triangle whose sides are 15, 14 and 13 unit. Find the radius of circle.

  1. 6 unit

  2. 5 unit

  3. 4 unit

  4. 7 unit
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

For triangle with sides a=15, b=14, c=13: semi-perimeter s = (15+14+13)/2 = 21. Area using Heron's formula: √(s(s-a)(s-b)(s-c)) = √(21×6×7×8) = √7056 = 84. Inradius r = Area/s = 84/21 = 4 units. Option A (6 units) and D (7 units) are incorrect. Option B (5 units) doesn't satisfy the formula.

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