What is a football commonly known to be made of?

Answer 1

A rectangle.

Answer 2

Well,

Local pitches are going to be grass, obviously.

Small stadiums etc are probably grass too, maybe some being half astro turf*

Larger stadiums will mostly have half grass-half astro turf*/synesthetic(fake) grass

*Not sure about this 100%, but some smaller stadiums claim to be half and half

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Hope you find this helpful

Answer 3

It used to be made of pigskin. It is now made of a type of leather.

Answer 4

A football field :D