there are more then 100 methods...
If this rib is a triangle in sketch, meka a trapeze (rectangle + triangle), the triangle part of the trapeze is autside the cylinder, and the rectangle part is inside the cilindre.
Or creta it so as in the picture, and thick the face inside the cilindre (winth Thickness)...
Here i attached the cad part with history, please go through it. i hope its fulfill you expectation.
Answered with a tutorial: https://grabcad.com/tutorials/how-to-create-rib-on-cylindrical-part--1
AttachmentsRIB_FOR_CYLINDERICAL_FACE.CATPart, 111 KB
thanks nedim. by the way i tried your above method, but it wasn't much helpful...
hey the above ways are good but you find a great excess material at the cylindrical plane when you zoom in . it is better you use the blend option from surfaces, but for this you need to have the base feature . check out the model once and the above models you'll find the difference.
AttachmentsP.CATPart, 114 KB
i hope this helps
Answered with a tutorial: https://grabcad.com/tutorials/how-to-create-rib-on-cylindrical-part