What is the form version of a triangle​

An equilateral triangle has three sides of the same length. An equilateral triangle is also a regular polygon with all angles measuring 60°. An isosceles triangle has two sides of equal length. An isosceles triangle also has two angles of the same measure, namely the angles opposite to the two sides of the same length.

Explanation:

i believe their role is to instruct certain sections on when they are to join and when they are to stop