Answer:
Third side = 8.34 cm
Step-by-step explanation:
Given that,
The perimeter of a triangle, P = 22 cm
One side of a triangle, b = 9 cm
The area of the triangle, A = 20.976 cm²
The formula for the area of a triangle is given by :
![A=\dfrac{1}{2}\times b\times h\\\\h=\dfrac{2A}{b}\\\\h=\dfrac{2\times 20.976}{9}\\\\h=4.66\ cm](https://tex.z-dn.net/?f=A%3D%5Cdfrac%7B1%7D%7B2%7D%5Ctimes%20b%5Ctimes%20h%5C%5C%5C%5Ch%3D%5Cdfrac%7B2A%7D%7Bb%7D%5C%5C%5C%5Ch%3D%5Cdfrac%7B2%5Ctimes%2020.976%7D%7B9%7D%5C%5C%5C%5Ch%3D4.66%5C%20cm)
Perimeter = Sum of all sides
9 cm + 4.66 cm + x = 22
x = 22 - 13.66
x = 8.34 cm
So, the third side of the triangle is 8.34 cm.