Exactly, simple algebra. You could also use the, for example side shot of the dentle expnander, as Ive seen a link to the patent pictures some where on this site to get the hypotenuse. And the rest would be simple Geometry. It might be a few mm or 1/16th off but it could be reasonably ploted out and the near exact demensions of the gauntlets could be determined for all lengths by taking averages. I know the calc pad is known. Which means the exact size is available. The hose connectors, switches and other peripheral items are also known hence other points of reference. I dont think you could get more exact than that. I agree that the majority of the shots are at angles but there are a few direct shots. It would be interesting to see what comes out on the next cd if there are more pictures than what has been collected. Any way, just a thought I had.