The relationship between the sides of the polygon and the triangle follows an arithmetic sequence
The expression that represents the number of triangles is (c) n - 2
From the diagrams, we have:
Sides Triangles
5 3
6 4
8 6
The above can be represented as functions as follows:



Express 6 as 8 - 2

Express 8 as n

So, the expression that represents the number of triangles is (c) n - 2
Read more about sequence and patterns at:
brainly.com/question/24050043