Answer:
The perimeter of triangle ABC to the nearest unit is:
  14 units
Explanation:
We know that the perimeter of a triangle is the sum of length of all the sides of a triangle.
In the following triangle we have:
 Perimeter ABC=AB+BC+CA
We are given AB=3 units , BC=5 units and 

Hence, the perimeter of triangle ABC is:

  Hence, to the nearest unit we get:
 Perimeter is: 14 units.