I want to create a shape like the second image below. I created the first image below by creating a hole with boolean modifier, selecting the circle and extrude individual, etc. But how can I extend the the middle of the circle to the edge of the rectangle? I could do so by manually adding vertices and edges, but I am afraid that the result will not be precise. I wonder if there is a better way.
fudge.blend (127.4 KB)
Boolean not really necessary for a simple shape like this:
Start with a 16-vert circle that you mirror, and just build up the geometry from there (try to maintain quads and avoid n-gons)… Cursor pivoting is a necessity. Constrained-move combined with snapping helps.
Shade-smooth combined with bevel and sub-d modifiers gives the nice edges.
If I’m not making sense, google some “hard-surface modeling” tutorials and practice on simple shapes like this one, and it’ll be doable.
Good luck!
So you manually added each vertex for everything after the circle, and connected the vertices manually?
No. Do some hard-surface modeling tutorials then re-read my previous answer… it’ll all make sense 
Check out Grant Abbitt’s suggestions if you don’t know where to start:
Good luck and good-bye.
