Q5 of 26 Page 187

Calculate the area of a triangle of sides 13 centimetres, 14 centimetres, 15 centimetres.

Given sides, a = 13 cm, b = 14 cm, c = 15 cm


We know, area of triangle = √(s(s - a)(s - b)(s - c))


Where, a, b and c are sides and s is the semi-perimeter calculated as



∴


⇒ area = √(21(21 - 13)(21 - 14)(21 - 15)


= √(21 × 8 × 7 × 6 ) = √( 7 × 3 × 4 × 2 × 7 × 3 × 2)


= 7 × 3 × 2 × 2


= 84 cm2


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