1. The document defines important terms related to circles such as radius, diameter, chord, arc, sector, and segment. It also provides the relationship between degrees and radians. 2. Formulas are presented for calculating the length of an arc, perimeter of a segment, area of a triangle formed by the radius and a chord, area of a sector, and area of a segment. 3. Instructions are given on how to convert between degrees and radians using a calculator and how to find sine, cosine, and tangent values for angles measured in radians.

1. All in One CIRCULAR
IMPORTANT TERMS 1. Definition : 1 IMPORTANT FORMULAE
r r
radian
θ IN RADIAN
1 jejari
Minor 2. Important relationship
segment r A
o
O diameter 180 = π radian
major π r
chord 1
o
= 180 radian C
O θ
segment
0
180 r
tangent 1 radian = B
π
Minor arc
3. To change the unit .
2.
( s AB ) = r
0
Example : Convert 30 to radian:- 1. Length of arc AB
Major arc
0
π
Minor sector 30 = 30 x 180 radian
O
Major sector OR using calculator casio fx 570 ms)
30 shift DRG 1 = 3. Perimeter of segment ABC
i) Change to radian mode
ii)
= sAB + chord AB
= r + 2 r sin
H r
BASIC FORMULA
θ 4. To find the sin , cos or tan for the
A 4. Area of triangle OAB = r 2
r angle in
O sin
Radian using calculator
θ
Example : Find sin 1.5 radian 5. Area of sector OAB = r 2
Method 1 : If in radian mode .
sin θ = O/H
SAB = 6. Area of segment ABC
cos θ = A / H A = sin 1.5 = = r 2( - sin )
Method 2: If in degree mode
Sin 1.5 shift DRG 2 =