Question

What made people come up with the idea of trigonometry?

Answer 1

Trignometery

Pythagoras theorem already told us that square of hypotenuse is equal to that of sum of squares of perpendicular and base.

But in the case, where we don't have length but only know angle of elevation then it was hectic to measure length of any distance.

This is how, Trignometeric idea came up where on the base of Trignometeric values itself we can determine length of hypotenuse, base and perpendicular.

The only need is to have a right angle at some point of triangle.