How to decode this drawing

[nordestgaard]

I am doing some excercises to master Inventor. However this one is killing me.

How the h... do I find/calculate the measures in the red marked area.

Any hints will be appreciated and probably save my sleep tonight.

 

[MrCATIA]

Hope you didn't miss your sleep. Looks to me like there is a dimension missing on the left side for the inside radius,

 

[dstrausser]

Agree - you are missing a dimension