Q)
(chatquestion)...finition 2 AOP
circle and cut off as,
BLATION BETWEEN DEGREES AND RADIAN
GAand eutoff an
ton the drle e duce AO to meet
Twesador a de wish centre Oandradtheer Let Ateapo 1 radian
n d length egual to the radnesof the circde The
AOB-a straight angle-2 right angles
m e ares subtending them
We Amow that the angles at the centre of a circle are proportional
them.
are AP
arc APB
LAOP
2right angles
Circumference)
are APB
rightangles
2-
Fig. 4.11
180°
Hence, One radian =
180°
→ n radians = 180°.
REMARK I Clearly, arc (APBQA) = 2 nr. So, the measure of angle made by this arc at this centre O of
Om pelr
the measure of this angle is the measure of one revolution i.e. 360°.
2nradians = 360° = T radians =180°
2nr
radians i.e. 2n radians.
the circle is
fre of the unit circle shown in Fig.
Зп
radians.
3
Sinceone complete revolution subtends an angle of 2n radians at
(27)
4
%3D
=(2)= t radians and, 4AOD :
are integral multiples of All integral multiples of
2
ZAOB ==x2n =" radians, LAOC=
are called the a
Thus, quadrant angles
ngles.
a constana
...
