Frame Perimeter?

A little clarification here please:
A rule states that the ball cannot enter more than three inches into the frame perimeter. The frame perimeter is defined as the the furthest extending verticies of the robot; so my question is can I build a U-shaped chassis and have the ball enter into the center of the U as long as it does not pass under any component?


The frame perimeter is defined as though a rubber band were stretched around the robot at the level of the bumpers.

Thank you. That clarifies that for us, one design down many too go.