The world of geometry just witnessed a pivotal breakthrough. Mathematicians at Monash University have cracked a centuries-old puzzle dating back to the 17th century, extending Descartes’ Circle ...

A tangent is a straight line which touches the circle at a point but does not cut through the circle. There are two theorems involving tangents. The angle between a tangent and a radius is 90°..

In high school, you probably learned that trigonometric functions – like sine, cosine and tangent –can be derived, geometrically, from a circle (hence ... on this post by math visualization ...