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 ...

Save guides, add subjects and pick up where you left off with your BBC account. To find the equation of a circle when you know the radius and centre, use the formula \({(x - a)^2} + {(y - b)^2} ...