Question

If a triangle has sides 6 feet and 9 feet and the perimeter is 23 feet, how long is the third side?

Short answer

Third side of triangle =$8feet$

Step-by-step solution

Step 1. Given information

Perimeter of the given triangle=$23$

Let one side of the triangle 'a'=$6feet$

Let second side of the triangle 'b'=$9feet$

Step 2. Finding the third side 'c' of the triangle.

Formula of perimeter of a triangle = $a+b+c$

localid="1647092533787" $$\begin{gathered} 23=6+9+c \\ 23=15+c \\ 23-15=c \\ 8=c \\ c=8 \end{gathered}$$

Step 3. Checking

Check the solution by using the formula $P=a+b+c$

$$\begin{gathered} 23=6+9+8 \\ 23=23 \end{gathered}$$ [true]

Therefore,third side of triangle$c=8feet$