1
$\begingroup$

I understand the usual way to construct a torus. i.e., pasting opposite edges of a rectangle.

But I don't know the construction by saying take a zero cell and attach a two one cell and then attaching a two cell.

Also construction of a orientable surfaces of genus 2g from a polygon with 4g sides.

I am not able to imagine. Could you please help me to imagine this?

Thanks in advance.

2 Answers 2