How to reform geometrically (reshape) equilateral Triangle into Rectangle?
Best option is to do it on shortest path (it's quickest, safest and cheapest) move.
In equilateral triangle with base at bottom, upper node (point) is exactly half way between lower nodes (on X axis, above Triangle base). So shortest path is to transform it into two points and move them to sides.
To reshape equilateral Triangle into Square we must move upper point upwards (until it reaches height equal to the original Triangle's side length) before transforming it into two points and moving them to the sides.
(See also Shapes and Forms, Stitie Machine, Dragonfly Algorithm, Virtual Machine and comment to Few Thoughts on Java Code Quality. You can be creative.).