A. PERIMETER AND AREA OF A CIRCLE
 The distance covered by travelling once around a circle is called the perimeter
of the circle. It is also called the circumference of the circle.
 Circumference =
o =
o =
 Area of the circle =
B. AREAS OF SECTOR AND SEGMENT OF A CIRCLE
S
Major Sector
O
Minor Sector
P
Q
R
 Sector of a circle
 The portion / part of the circular region enclosed by two radii and
the corresponding arc is called a sector of the circle.
 Area (minor sector OPRQ) =
 Area (major sector OPSQ) =
= area of the circle
minor sector
area of the
 Length of an arc of a sector of angle
=
where, r = radius of the circle
 Perimeter of the sector
=
+ 2r where, r = radius of the circle
 Segment of a circle
 The portion/part of the circular region enclosed between a chord
and the corresponding arc is called the segment of the circle.
 The segment containing centre of the circle is called major
segment and the segment which doesn’t contain the centre of the
circle is called the minor segment.
 Area of minor segment PRQ
= Area of sector OPRQ – Area of
=
–
 Area of major segment PSQ
= Area of circle – Area of minor segment PRQ
=
C. AREAS OF COMBINATIONS OF PLANE FIGURES
 Finding out the areas of figures made up of two or more figures
i.e. combination of figures.
 Finding the areas of different shapes, and add or subtract the areas
of another shapes to find out asked area.