How do I subtract the inner path from the outer circle in Adobe Illustrator?

Question

Imagine if you took the following shape...

...and flipped it on its side in a three-dimensional space. I'm trying to do that in Illustrator, and so far I have this:

From the outer circle, I want to subtract the {inner circle + the shape bounded by the two yellow straight lines, the inner circle, and the outer circle}.

I tried selecting everything and using Object > Compound Path > Make, but that leaves me with this:

As you can see, {the shape bounded by the two yellow straight lines, the inner circle, and the outer circle} is not being subtracted from the outer circle.

I also tried joining the outside edges of the two straight lines using the pen tool, then using Compound Path. But making a perfect bezier curve that traces over the outer circle exactly is too much for my human fingers -- so there's a faint line where the fill from the compound path doesn't completely overlap.

How can I subtract the {inner circle + the shape bounded by the two yellow straight lines, the inner circle, and the outer circle} from the outer circle?

Answer 1

1) You can also do this using Knockout. This is a non destructive method.

1. Make the parts you want cutout white.
2. Then group objects (CTRL/CMD + G).
3. In the Transparency Panel click on Knockout Group.
4. Select the white objects with the Direct Select Tool (A), go to the Appearance Panel and set the Fill to 0

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2) You can also use Minus Front if you have the objects above the circle. Use a rectangle instead of the 2 single paths.

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3) If you do use paths instead of a rectangle, you can use the Trim function in Pathfinder and then delete that area.

In the gif above I use the Trim function, then ungroup, lock the black object and delete the rest.

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Tip: Note sure if you already do this but it is easier to create the effect before you change the perspective of the shape.

Answer 2

One other approach is to use the Shapebuilder tool, rather than Pathfinder. Shapebuilder lets you work more visually with your art.

Here's a link to a quick screencap movie on how to use it: https://www.dropbox.com/s/8fu3lrd744civk0/ShapebuilderToolAI.mov?dl=0

You can also color art with Shapebuilder. Here are a couple of addtional resources on how to use it, from simple: http://adobe.ly/1U0oh4I to more complex: http://adobe.ly/1U0olkR