Have you heard of the missing square puzzle? Well here's an explanation of at least one way that this works. Now can someone figure out how to make this work with pie...? #shorts
Forget formulas. Draw that larger triangle on graph paper, then draw the inner shapes. You'll easily see the gap at the corner, revealing that the 'trick' is a *deception* born of making the pen lines thicker and losing some material in the scissoring. Rounding errors with a deceptive presentation.