NCERT Exemplar Solutions
Class 6 - Mathematics - Unit 9: Symmetry and Practical Geometry - Multiple Choice Questions

Question 9

A circle is the set of all points that are at the same distance from a fixed point (the centre).

To draw a circle, we need an instrument that can:

• Fix one leg at the centre (O).

• Keep the pencil at a fixed distance (the radius) (r).

• Rotate around (O) to mark all points at distance (r).

Check each option:

• Ruler: used to draw/measure straight lines, not circles.

• Protractor: used to measure angles in degrees, not to draw circles.

• Divider: used to transfer or compare distances, not to draw a circle.

• Compasses: a hinged two-leg tool with a needle and a pencil — exactly what we need to draw a circle.

How compasses work (small steps):

Set the centre: (O)

Choose the radius: (r)

Keep the needle at (O)

Keep the pencil (r) units away

Rotate a full turn: (360^circ)

All points are at distance (r) from (O) ⇒ a circle is formed.