What is the standard time?based on which longitude is the Indian Standard Time determine

I believe the answer would be 82.30′ E or 82.5 E

Humans have survived and thrived in mexico city by using technology to create greater access to land. when the spanish conquered the aztec capital, tenochtitlan, in the 16th century, they built mexico city by draining the lakes and filling in the lake water to create more arable land for agriculture. this technique of land reclamation has continued to be fundamental to human civilization in mexico city. 

2pi more meters because you find the circumference which is 6pi and 4pi and subtract it and you get 2pi