There are exactly π radians in a semicircle. There are exactly π radians in a full circle. There are approximately radians in a full circle. 2π radians is equivalent to degrees.

1. 2

2. 6.28

3. 360

ON EDG.

pi radians in a semicircle (half circle)

2pi radians in a full circle.

2pi = 2*3.14 = 6.28 approximately, so there are approximately 6.28 radians in a half circle.

2pi radians is equivalent to 360 degrees.