This means that, using Pythagoras’ theorem, the equation of a circle with radius \(r\) and centre (0, 0) is given by the formula \(x^2+ y^2= r^2\). Find the equation of a circle with radius 3 ...

Want to calculate the radius of a circle from its area or perimeter? Here are the key formulas that no one explains clearly! ...

The tangent is perpendicular to the radius which joins the centre of the circle to the point P. As the tangent is a straight line, the equation of the tangent will be of the form \(y = mx + c\).