Area related to circle

1. AREAS RELATED TO CIRCLE
(CLASS 10TH )
CIRCLE
MAJOR SECTOR
MINOR SECTOR

2. Area of the circle =
 Area of sector of a circle (θ in degree)=
 Area of sector of a circle (θ in radian) = ½r² θ
 r radius
 θ central angle

πr²
r
θ̶̶∕360° x πr²

3. SEGMENT
AREA OF SEGMENT OPTQ = (Asector POQT) – AΔPOQ
= (½) × r2 θ – (½) × r2Sin θ)
T
r r
Area of sector POQT= (½) × r2 θ
Area of triangle POQ= ½ X OM X PQ
= ½ X r Cosθ/2 x 2rSin θ/2
= ½ × r2Sin θ
M
NOTE – USE θ IN RADIANS

4. HOW TO CONVERT DEGREE INTO RADIAN
REMEMBER 360° = 2π
ANGLE Ꝋ (IN RADIAN) = π/180 X ANGLE IN DEGREES
EXAMPLE : CONVERT 45° INTO RADIANS
45° = π/180 X 45
45° = π/4 RADIAN