Circles Class 9 Maths Formulas – All Theorems, Properties & Quick Revision Guide

Home Class 9 Maths Circles Class 9 Maths Formulas What Is a Circle? Key Definitions A circle is the set of all points in a plane that are at a fixed distance from a fixed point. The fixed point is the centre and the fixed distance is the radius. Term Definition Centre Fixed point equidistant from every point on the circle. Radius (r) Distance from centre to any point on the circle. Diameter (d) Longest chord; passes through the centre; d = 2r. Circumference Total length of the circle = 2r. Under...