Reference angle of -3 radians is α= - 171° 53 min 15 sec .
We know the formula for calculating circular arc
Let l=circular arc which ic according to central angle of the circle α
l=((2R π)/360)α Let l=1 radian and R=1 (unit circle with radius R=1)
1= ((2π)/360)α => α= 360/(2π)= 180/π= 57° 17 min 45sec
Angle of the 1 radian is equal to angle 57° 17min 45sec
According to this
angle of the -3 radians = -3 ( 57° 17min 45sec) = - 171° 53min 15sec
when you count in the clockwise direction.
Good luck!!!