, ▁it ▁is ▁called ▁geometry ; ▁when ▁applied ▁to ▁the ▁construction ▁of ▁plans ▁of ▁edific es , ▁it ▁is ▁called ▁architecture ; ▁when ▁applied ▁to ▁the ▁measurement ▁of ▁any ▁portion ▁of ▁the ▁surface ▁of ▁the ▁earth , ▁it ▁is ▁called ▁land - sur ve ying . ▁In ▁fine , ▁it ▁is ▁the ▁soul ▁of ▁science . ▁It ▁is ▁an ▁et ernal ▁truth : ▁it ▁contains ▁the ▁mathematical ▁demonstr ation ▁of ▁which ▁man ▁speak s , ▁and ▁the ▁extent ▁of ▁its ▁uses ▁are ▁unknown . ▁ ▁History ▁ ▁Great ▁Tr ig on omet rical ▁Survey ▁ ▁From ▁ 1 8 0 2 ▁until ▁ 1 8 7 1 , ▁the ▁Great ▁Tr ig on omet rical ▁Survey ▁was ▁a ▁project ▁to ▁survey ▁the ▁Indian ▁sub cont inent ▁with ▁high ▁precision . ▁Starting ▁from ▁the ▁coast al ▁bas eline , ▁mathemat icians ▁and ▁ge ograph ers ▁tri ang ulated ▁vast ▁distances ▁across ▁the ▁country . ▁One ▁of ▁the ▁key ▁achiev ements ▁was ▁meas uring ▁the ▁height ▁of ▁H imal ay an ▁mountains , ▁and ▁determ ining ▁that ▁Mount ▁Ever est ▁is ▁the ▁highest ▁point ▁on ▁Earth . ▁▁ ▁Historical ▁use ▁for ▁multiplication ▁ ▁For ▁the ▁ 2 5 ▁years ▁preceding ▁the ▁in vention ▁of ▁the ▁log arith m ▁in ▁ 1 6 1 4 , ▁prost h ap ha er esis ▁was ▁the ▁only ▁known ▁generally ▁applicable ▁way ▁of ▁approxim ating ▁products ▁quickly . ▁It ▁used ▁the ▁ident ities ▁for ▁the ▁trig on ometric ▁functions ▁of ▁sums ▁and ▁differences ▁of ▁angles ▁in ▁terms ▁of ▁the