Ever since the old equations box was replace more than a few years back, I have been using workarounds to avoid equations. Every so often I try it again and "The syntax of this equation is incorrect". It's annoying because the same thing used to work and was quite useful. Usually it is something that should be simple such as "D4@Sketch21=D4@Sketch20" or "D3@Sketch28=D5@Sketch22*1.5".
Is there a way to set up an equation by clicking a dimension inside a sketch and telling Solidworks that it equals a dimension in another sketch? Or even that it equals another dimension from another sketch divided by or times a number? There must be a way do drive a dimension in one sketch from a dimension in another that I'm not finding.
You can easily (sorry, I didn't mean to sound condescending) add an equation into the dimension dialog
Or, once you've dimensioned something, you can double click it and write a name for it and it making a global variable that you can then re-use as you like.