Answer:
17 cm
Step-by-step explanation:
To find the perimeter of any figure, you must add all the side lengths. In a triangle, there are three side lengths to add, and in this case, they are 3 cm, 6 cm, and 8 cm long. So:
3 + 6 + 8 = 17 cm
∴, the triangle's perimeter is 17 cm.