Hi everybody.

Not sure if I’m going to use the right English words to describe what I’m looking for.

My intention is to draw a circle circumscribed and tangent to other two.

Let’s suppose I have a circle called A and another one called B.

I’d like to know how I can find

- the center of the arc I drew in “red/pink”
- the tangent points of the big circle on A and B.

I know TIG developed an awesome extension called True Tangents, not sure if it can help in this situation but I wasn’t able to use it to solve this situation.

I know little maths and nothing about architecture, but all kind of help will be appreciate.

Thank you so much.