Maths Class 11 Chapter 3. Trignometric functions | Page 3

Degree Measure o 1 ° = 1 / 360 th of rotation . ( 1 complete rotation = 360 degree ) o 1 ° = 60 ′ ( 1 degree = 60 minutes ) o 1 ′ = 60 ″ ( 1 minute = 60 seconds ) Lets draw 360 °, 180 °, 270 °, 410 °, – 30 °, 50 °
Notice that Angles 410 o & 50 o are same , Radian Measure : o
o
( 410 o -360 o ) = 50 o
1 radian is the Angle subtended at centre by arc of length 1 unit in a circle of radius 1 unit .
One revolution = 2π radian