2. CIRCLE

3. Circle is the locus Of all poins equidistant From a central poins

4. Diameter Radius centre The diameter of the circle is the distance from one side to the other passing through the centre of the circle The radius is the line connecting the centre of the circle and the circumerence

5. Relation between radius and diameter. O AB RADIUS = DIAMETER 2 Diameter = 2 x Radius

6. O Centre A circle A The circumference is the distance around the circle.

7. The Perimeter or Circumference of a Circle A circle is defined by its diameter or radius Diameter radius The perimeter or circumference of a circle is the distance around the outside The ratio of π (pi) π is an irrational number whose value to 15 decimal places is π = 3.14159265358979.... We usually say π ≈ 3.14 The circumference is found using the formula C=π d or C= 2πr (since d=2r)