Question

sides of triangle are 70 cm 80 CM 90 cm find its area

Answer 1

Let the sides of the triangle be
a = 70cm
b = 80cm
c = 90cm
Semi perimeter
$= \frac{a + b + c}{2} \\ = \frac{70 + 80 + 90}{2} \\ = 120cm.$


Area of the triangle
$= \sqrt{s(s - a)(s - b)(s - c)} \\ = \sqrt{120 \times (120 - 70) \times (120 - 80) \times (120 - 90)} \\ = \sqrt{120 \times 50 \times 40 \times 30} \\ = \sqrt{3600 \times 2000} \\ = \sqrt{36 \times 20 \times 10000} \\ = 100\sqrt{36 \times 20} \\ = 600 \sqrt{20} \\ = 1200 \sqrt{5} {cm}^{2}.$



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Answer 2

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