For https://scratch.mit.edu/discuss/topic/261792/ tweak the slider to alter the base size of these objects. The width and front-to-back depth of each is set equal to the height.
(isometrics for the cylinder aren't 100% but an exact solution requires some fancy ellipse maths that are beyond this quick hack. The ellipse needs to be rotated to fit in the same trapezium as the top of the cube, and it should touch that sheared square at the center point of each side.) For teaching purposes, it would be nice if the cylinder and the prism could be slid sideways into the same footprint as the cube.
