Same as anywhere: opposite to a clock's conventional rotation. Mathematicians like to put x = 0º on the x-axis (so y = Sin x = 0) and measure anticlockwise from there.
Chat with our AI personalities
plane trigonometry spherical trigonometry
The main kinds are plane trigonometry and solid trigonometry. The latter will include trigonometry in hyper-spaces.
Hipparchus is the father of trigonometry.
Trigonometry based on a unit circle and radians and trigonometry based on a right triangle.
Hipparchus of Nicaea