4 of 7. Besides the beam angle there is also the so-called field angle.In the light circle, the beam angle defines the area where the lamp radiates at least half (50%) of its maximum luminous intensity. 270 Degree Angle. It is not an SI unit, however, it is accepted for use with SI. Hi! What are some real world examples of 180 degree angles? study (3/16") 20 mm, Finish: Nickel, Material: Steel, Opening angle: 270 degree opening angle with a … Find the bearing of an airplane located at each point. Half of a turn is 180 degrees. –270° Some angles have special names: an angle of 180° is called a straight angle, and an angle of 90° is called a right angle.