A circular shape or object is one that is in the form of a circle. How many of these circular objects can you name? The radius (or ‘radii’ for plural) is the length of a straight line from the ...

by a straight line that forms the hypotenuse of a right angle triangle with sides of length \(x\) and \(y\). This means that, using Pythagoras’ theorem, the equation of a circle with radius \(r ...