So I was watching a video that features astronomer and topologist Cliff Stoll talking about how figures that aren't quadrilaterals can have all their angles equal 90 degrees on different surfaces. For example, on a sphere, you can create a triangle that has all of its angles equal $90^\circ$. On a pseudosphere, you can create a pentagon that has all of its angles equal $90^\circ$. Now, here's my question. 

> 
> Is there a surface where a hexagon with this property is possible?
> 
> 
>