Answer:

Step-by-step explanation:
Basically, the problem is asking to make an triangle but without labeling its sides as number, but as algebraic expression.
So, let's say that all three sides are

Now, remember that the perimeter is the sum of all sides of a figure, so in this case would be

To simplify this expression, we just need to reduce like terms as follows

Therefore, the simplified expression of the perimeter is

The image attached shows the triangle we used.