Problem
6. a) Write an expression in simplest form for the perimeter of the triangle below. b) Find the perimeter if the value of $x$ is 3 .
Solution
Step 1 ：Write the expression for the perimeter: P = a + b + c
Step 2 ：Substitute x = 3 and calculate the perimeter: P = 7 + 7 + 7 = 21
Step 3 ：The final answer is: \( \boxed{21} \)
