Describe two ways in which you can find the perimeter of the pentagon

You can find the perimeter of a pentagon by its vertices or by using an unit circle

This is true. The term congruent means that the shape is of exactly equal size. If this is true, then every side length would match for each shape. If this is true, the perimeter would also be exactly the same for each shape. Think of something that is congruent as being an exact copy of the original, with no change in size or shape.