The radian measure of 270 degrees is 4.71238898038469. A radian is a unit of measurement used mainly in trigonometry, which is the study of triangles and how their angles are related to each other. The definition for a single radian is the angle formed when you draw an arc that has the same length as the radius of a circle from its center point, so one full rotation (or 360 degrees) in a circle would equal 2π (approximately 6.2831853) radians.

To convert between degrees and radians, we can use this formula: Radians = Degrees * π / 180°; therefore, we can calculate that 270 degrees equals 4.71238898038469 Radians when we divide 270 by 180 and then multiple it by pi (3.14159). It’s important to note that this calculation only works when converting from degrees to radians; if you want to go the opposite direction, you must use Degrees = Radians * 180° / π instead.