Arc length is a fraction of circumference. Area of a sector is a fractions of the area of a circle. Both can be calculated using the angle at the centre and the diameter or radius. Practice circle ...

Google has quietly upgraded their search calculator to not just answer your basic math questions or graphical or 3D math questions; now, it can do your geometry homework. You can ask Google geometry ...

In the third century BCE, Apollonius of Perga asked how many circles one could draw that would touch three given circles at exactly one point each. It would take 1,800 years to prove the answer: eight ...