Sphere Slices with Equal Surface Area
Inspired by this tweet from Fermat's Library, the claim is made that "If you put a spherical loaf of bread through a bread slicer [with equal slice thicknesses], then each slice comes out with equal crust."
Calculus proof provided with with the tweet.
This visualization maybe doesn't illuminate the conclusion as much as I had hoped it would, but it was fun to create. "Un-revolving" the surface by dragging to a small value such as 45° may make it easier to visually judge whether each slice appears to have the same surface area.