**There is a slide in a park. One of its side walls has been painted in some colour with a message “KEEP THE PARK GREEN AND CLEAN” (see figure). If the sides of the wall are 15 m, 11 m and 6 m, find the area painted in colour.**

**Solution:**

Length of first side of triangle **m**

Length of second side of triangle **m**

Length of third side of triangle **m**

Semi-perimeter of triangle **m**

Using** Heron's formula** to find area of triangle, we get

Area of triangle