I was wondering, what book did people use in the 17 th century to learn trigonometry as it was before ? Just general curiosity...
As it turns out, Bartholomaeus Pitiscus is known as the person who introduced the word trigonometry into the English language in the sense that we understand the word today. In 1595 he produced Trigonometria: sive de solutione triangulorum tractatus brevis et perspicuus, and this seminal work was, throughout the 17th century, translated into English several times.
I know this book was translated to English a few times throughout the 17th century, but I can't manage to find a good download link at the moment.
Pitiscus' book was certainly not the only trigonometry book used in the 17th century, but it stands out as being a very important historical example, and one which I think deserves mention.