convert degrees to radians, multiply by π/180° , since a full circle is 360 ° 360 or 2π radians.
− 405°⋅ π /180° radians
Cancel the common factor of 45 .
-9 ⋅ π/4 radians
Combine −9 and π/4
-9π/4
Move the negative in front of the fraction.
-9π/4 radians