Question

Geometry.
A sphere of radii R at centre O.
A disk of radii r is in it at centre A.
I need sin(theta) in terms of r and R.

Answer 1

Is the diagram clear?

Answer 2

Is it a flat diagram, because if not, then you have to add a second view

Answer 3

No it's not.
There is a hemisphere.
And the line in between is basically a disk of radii r.

Answer 4

Centered at A.

Answer 5

any other parameter?

Answer 6

No.

Answer 7

It is multi-meaningful without more data

Answer 8

perhaps you don't have unique value of theta without any other parameter.

Answer 9

Okay. Possibly. I'll recheck then post the question.