[Swizec]

My middle school physics teacher taught us to build those formulas by reverse-engineering the units. This was before we had done enough algebra to know what we're doing so we used triangle diagrams, but boy was it the best thing I ever learned.

Don't understand what something is? Just look at the unit. It tells you!

[jacobolus]

What’s a triangle diagram?

[barrkel]

     a
    b c

encodes

  a = b * c
  c = a / b
  b = a / c