Construct a convex octagon with four right angles. It probably says a lot about me as a teacher that I assign problems like this. I watch as students try to arrange the right angles consecutively.

Dive into one of the most wicked geometry problems and see it explained step by step in a clear, intuitive way. This lesson ...

Gear-obsessed editors choose every product we review. We may earn commission if you buy from a link. Why Trust Us? A mathematician may have just proved the impossible possible. For 30 years, ...