You might find the following interesting. It is about trigonometry as practiced by early Indian mathematicians. Rather than using an unit circle they used a cir

You might find the following interesting. It is about trigonometry as practiced by early Indian mathematicians. Rather than using an unit circle they used a circle of 3438 units. https://news.ycombinator.com/item?id=45129081 https://news.ycombinator.com/item?id=45129081 Now it is customary to standardized on the radius. Early Indian astronomers and mathematicians standardize on the arc length of a minute.