A circle is defined as all points in a plane that are equidistant from a fixed center point. The center point is called the center of the circle, and the fixed distance from the center is called the radius. The longest chord that can be drawn through the center is the diameter. If two chords of a circle are equal in length, then their distances from the center are also equal, as proven using the Side-Side-Side congruence rule for triangles.

3. •A circle is the collection of all points in
the plane, which are equidistant from a
fixed point in the plane.
• A circle is a plane figure.
• Euclid discovered the circle.
•The fixed point is called the centre of
the circle
• The fixed distance is called the radius
of the circle.
• The longest chord of the circle is the
diameter of the circle.

4. If the length of two chords
are equal then their
distance from centre is
also equal.

9. D
O
A
C
B

10. O is the centre.
AB and CD are two equal chords.
Angle AOB = Angle COD

11. In AOB and COD
AO = CO (Radius of
circle)
AB = CD (Given)
OB = OD (Radius of
circle)
By SSS Congruence rule,
AOB is congruent to COD
By c o r r e s p o n d i n g p a r t o f
c o n g r u e n t t r i a n g l e
A n g l e A OB = A n g l e COD

12. Harsha Detani 9031
Dimple Tak 9024
Nikita Soni 906
Harshita Tomar 2
903
5
Heena Detani 903
Kriti Singhal 6
904