In this video Grant Sanderson https://youtu.be/GNcFjFmqEc8 said about how the sphere can be approximated as rectangles , we can surely make quadrilaterals because we can cut the sphere in $n$ equal parts from top and then making slices in each of them which are flat .
For approximation but then how does 3b1b said that there are rectangles ? Isnt that actually are isosceles trapeziums in general ? Even the picture depicting the conversion from sphere to approx rectangles are actually isosceles trapeziums isnt ? So why saying rectangles ?