Pie Menu/Inventory

Does anyone have an idea how to make this? More specifically one similar to this

I know this one is in the marketplace, but ive spent plenty of money there already.
I have not found any tutorials.

Use basic trigonometry to arrange symbols in a circle:

alpha = (PI*2)/numOfItems

x = sin(alpha*i)radius;
y = cos(alpha

The rest of it is Material that draws a colour in a certain angle with an outer and an inner circle given.

Ok so if i want the x and y cord of a certain piece, i fill in that equation
alpha = (PI*2)/8


so what is I? also doesnt that just put them all in the same position? or is that where I comes in?

You do it in a for loop:

for(int i  = 0; i < numItems ; ++i)
  x= ...
  y= ...

Unreal Engine 4 Proof of Concept - Pie Menu