My Technic math puzzle of the day

[N. W. Perry]

I evidently solved this problem with the 8880 in the OMR. Maybe you can look at that for clues?

The OMR model keeps the control arms horizontal, so there's some collision between these parts. (For whatever reason, the IRL set has these parts to prevent just that arrangement—perhaps because they hadn't come out with the stiff shock absorbers yet?)