If you observe the triangle, you can see that all of its sides are equal. They are all s, or 6.3 mm. This means that to find the perimeter of the triangle, you can do either of two things:
1. You can multiple s by 3.
2. You can add s three times.
Either way, you will get the same answer. 6.3 • 3 = 18.9, and 6.3 + 6.3 + 6.3 = 18.9
If I am understanding the question correctly, then "type" means the type of triangle this triangle is. To figure this out, look at the measurements of the triangle. All of its sides are equal in length. That means that it is an equilateral triangle.
I know some schools like students to write "equilateral acute" triangles, since all of the angles are less than 90˚. If you want to be sure, I'd contact your teacher and ask.
