Scaling - maybe I don't understand math


I wanted to get a better understanding of the Rhino Scale Command.

If I have a square at 6.5 all sides and another square at 3.25 all sides then click both to scale proportionately and scale the 6.5 by an increase of 1 to 7.5… the small square becomes 4.75. Shouldn’t the small square be 4.25 to maintain the relationship to the starting dimensions and not necessarily each other?

Thank you,

Hi RP - I get 3.75 on the smaller square, as I’d expect… The scale factor for 6.5 > 7.5 is 1.154.


Scale factors work by multiplication, not addition. When two different size objects are scaled by the same factor the ratio of the size of the objects remains the same (size A / size B), not the difference (size A - size B).

Ah yes. Factors of multiplication.

It’s a funny problem to think of scaling as addition.

Thank you both!