Does anyone here live within 23 degrees of the equator?

Hey, I'm starting a physics project in which I am attempting to calculate the circumference of the Earth, and for my method I need someone who lives within 23 degrees of the equator to give me a hand! If you, or anyone you know, lives within this distance, please please please let me know! Thanks

How would a person know they were 23 degrees from the equator if other geometrical properties (eg circumference) of the earth are not known?

We do know the circumference of the earth, sorry for not being clear but I am trying to "recalculate" it, attempting to get a result using no computers, maps, calculators etc.
It's easily 'googleable' to find out where the 23° boundary is

Surely asking someone who lives below the 23rd parallel is using a computer?