A circle is a simple shape consisting of all points in a plane that are a given distance from a central point called the center. The distance from the center to any point on the circle is the radius, which is half the diameter or the distance across the circle. A chord is a line segment connecting two points on the circumference of a circle. The circumference of a circle can be calculated using the formula C=2πr or C=πd, where r is the radius and d is the diameter. The area of a circle is calculated using the formula A=πr^2, where r is the radius.

2. Circle
 A circle is a simple shape of
Euclideangeometry
consisting of the set of points
in a plane that are a given
distance from a given point,
the centre. The distance
betweenany of the points
and the centre is called the
radius.
center
F
Circle F

3. Radius Diameter
 In classical geometry, a
radius of a circle or
sphere is any line
segment from its center
or axis of symmetry to its
perimeter. By extension,
the radius of a circle or
sphere is the length of
any such segment, which
is half the diameter.
In geometry, a diameter of
a circle is any straight line
segment that passes
through the center of the
circle and whose
endpoints are on the
circle. The diameters are
the longest chords of the
circle

4. Parts of circle
chord
diameter
radius

5. Properties of circle
 A mid point of a circle is
known as Center.
 A line which is attached
the two edges of a circle
known as Chord.
 A chord which pass
through the center of a
circle is called Diameter.
 A line which is attached to
the center and one edge of
a circle is called Radius. it is
half of diameter.
chord
center
diameter
radius

6. Formulas
radius
diameter
Radius/diameter
radius =
½diameter
r = ½ d
diameter =
2(radius)
d = 2r

7. Circumference &area of
circle
➢The area of a
circle(the region
inside a circle)is πr2
when the circle has
radius r. Here the
symbol π denotes, as
usual, the constant
ratio of the
circumference of a
circle to its diameter.
•The circumference is the
distance around a closed
curve. Circumference is a
special perimeter.
•The circumference of a
circle is the length around
it. The circumference of a
circle can be calculated
from its diameter.

8. Circumference & Area of
circle
area = ∏r
circumference
2 Circumference
C = 2∏r
Or C = ∏d
radius

9. chord
A chord of a circle is a
geometric line
segment whose
endpoints both lie on
the circumference of
the circle generally a
chord is a line
segment joining two
points on any curve.
chord

11. MINOR SECTOR OF CIRCLE
A sector in which the angle
between the two radii is less
than 180∘

12. MAJOR SECTOR OF CIRCLE
When a circle is divided by two radii
into two unequal parts, the larger part
is called the major sector.

14. MINOR SEGMENT OF CIRCLE
When a circle is divided into two
segments by a chord, the smaller of the
two segments is called the minor
segment.

15. MAJOR SEGMENT OF CIRCLE
The larger area formed when a
circle is divided in two by a
chord.