mathematics - What's the word for the small square indicating a

I'm talking about something in geometry notation and/or drafting, I think. It's the mini right-angle shape you can draw within an angle to indicate that it's ninety degrees. E.g., the mark denoting

Plot Points on a Graph - Math Steps, Examples & Questions

Scale Factor, Definition, Calculation & Examples - Lesson

Square - Wikipedia

Reciprocal - Definition & Examples

Squared

square ~ A Maths Dictionary for Kids Quick Reference by Jenny Eather

Angle - Wikipedia

Can someone explain to me what an integral is? All of the definitions online are complicated as hell. : r/askmath

Right angle - Wikipedia