MathematicsClass 6Basic Geometrical Ideas
Circles
Learning the anatomy of a circle including its center, radius, diameter, chord, and circumference.
Class 6 · MathematicsCBSE & ICSE SOF IMO
Definition
A circle is a simple closed curve where every point on the boundary is at an equal distance from a fixed central point. The fixed point is the center, the constant distance is the radius, and a line segment passing through the center connecting two points on the boundary is the diameter.
Key formula
Diameter (d) = 2 * Radius (r)
Worked examples
1
A bangle, a coin, and a bicycle wheel rim represent circles.
2
Drawing a shape using a compass with the needle fixed at a point produces a circle.
3
The Earth's equator can be visualized as a circular boundary.
Common mistakes
- • Confusing the radius with the diameter by assuming the radius goes all the way across the circle.
- • Measuring the radius or diameter starting from the edge of the ruler instead of the zero mark.