Hipparchus is the father of trigonometry.
The largest contribution Claude Ptolemy made to trigonometry was the table containing the lengths of chords in a circle. This is one of the oldest tables still used in trigonometry today.
He defined the spherical triangle
He introduced coordinated geometry
There is no Contribution of Thales in the field of trignometry.........
Hipparchus is the father of trigonometry and he was a Greek astronomer who lived between 190-120 B.C. He is considered as the father of trigonometry, a branch of mathematics which studies the angles of sides of triangles. :)
spherical and plane trigonometry? :p
based on my stock knowledge, i think hipparchus is the father of trigonometry.....
An important contribution by Menelaus of Alexandria was his works on geodesics.