Question

9. There is a slide in a park. One of its triangular side walls has been painted in some colour with a message "ONLY FOR KIDS BELOW TEN YFARS^ " . If the sides of the wall are 9 m, 12 m and 15 m, find the area painted in colour. ​

Answer 1

Step-by-step explanation:

The area of any can be found using Heron's formula.

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

Where,

• $\rm a = 12\: m$
• $\rm b = 9 \:m$
• $\rm c = 15 \:m$
• $\rm s = \dfrac{a+b+c}{2}=18$

So, plugging in the values we get,

$\rm Area = \sqrt{18(18-12)(18-9)(18-15)}$

$\rm Area = \sqrt{18(6)(9)(3)}$

$\rm Area = \sqrt{18(18)(9)}$

$\rm Area = \sqrt{(18×3)^2}$

$\rm Area = 18×3=\bf 54\: m^2$