Question

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Not understanding why we're doing some of these steps.

Why does it form an isosceles triangle?
(I read the explanation but it's not quite clicking)
Why are we diving by 360 to find angle 1?

Also, why does the apothem evenly divide the section formed by two radii?

Answer 1

I guess the easiest way is to know all "regular" polygons fit in a circle
regular means all the sides are equal, and all the angles are equal.
Or more easily, all the sides are equal, and are chords of a circle

for example

square and an equilateral triangle.

notice the "corners" or vertices all lie on the circle, so the distance from the center to a vertex is a radius. (i.e. all the same distance). this is how you get isosceles triangles