Question

Sides of a triangle are in the ratio of 3:5:7 and its perimeter is
120 cm, then area of this triangle will be.​

Answer 1

Answer:

here is the answer

Explanation:

the area of triangle is 10392.3048 sq. cm

Answer 2

$let \: the \: sides \: of \: \triangle \: be \: 3x \: 5x \: \: and \: 7x \\ perimeter \: of \: \triangle = 3x + 5x + 7x \\ 120 \: cm = 15x \\ x = \frac{120}{15} = 8 \: cm \\ side \: : - \\ 3x = 3(8 \: cm) = 24 \: cm \\ 5x = 5(8 \: cm) = 40 \: cm \\ 7x = 7(8 \: cm) = 56 \: cm \\ area \: of \triangle \: = \sqrt{s(s - a)(s - b)(s - c)} \\ where \: \\ s = \frac{perimeter}{2} = \frac{120 \: cm}{2} = 60 \: cm \\ a = 24 \: cm \\ b = 40 \: cm \\ c = 56 \: cm \\ area \: of \triangle \\ = \sqrt{60(60 - 24)(60 - 40)(60 - 56)} \\ = \sqrt{60 \times36 \times 20 \times 4 } \\ = 6 \times 2 \times 10 \times 2 \sqrt{3} \\ = 240 \sqrt{3} \: cm {}^{2}$