Question

find the area of the triangle when three side of its is 10 cm ,12 cm,and 18 cm​

Answer 1

Formula to find Area of triangle when 3 sides are given:-

$\rm \dfrac{a+b+c}{2}=S$

$\rm \sqrt{s(s-a)(s-b)(s-c)}$

Here, a, b, c are the sides of the triangle and S is semi perimeter.

Using this formula,

$\rm\dfrac{10+12+18}{2}=\dfrac{40}{2}=20$

$\rm \sqrt{20(20-10)(20-12)(20-18)}$

$\rm\implies \sqrt{20(10)(8)(2)}$

$\rm\implies \sqrt{3,200}$

On further simplification, you will get 57cm² approx.

Hope it helps