Scaling measurements from a photo or sketch??

by Jerry
(San Diego, CA)

The page on this website that goes through the process of explaining the use of a 'diagonal' as the scale take off of measurements derived from the photo or sketch with the divider leaves a question open for me.

It is this : If line A, B is (in scale) 22'6" then why is the diagonal necessary??



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Feb 02, 2011
Measurement ratios
by: Mike

The point to the diagonal is to transfer proportions rather than actual distances.

That way you can take off several measurements and if you wish transfer them to a different scale without having to do the calculations for each one.

If all you wanted was one distance, then it would probably quicker just to do the maths.

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