Answer:
The perimeter of the triangle can be expressed as 5x + 18.
Step-by-step explanation:
Perimeter of an object is the sum of the length of its sides.
For the required triangle, we have;
length of the base = x
length of the second side = 3x + 9
length of the third side = x + 9
Perimeter of the triangle = length of the base + length of the second side + length of the third side
= x + (3x + 9) + (x + 9)
= x + 3x + 9 + x + 9
= 5x + 18
The perimeter of the triangle can be expressed as 5x + 18.
