Lengths OH and OG are also both radii. Angle GOH = \(180^\circ - 2y\) (because angles in a triangle add up to 180°). Angle JOK = \(2x\) (because angles on a straight line add up to 180°).

A 180-degree angle means that there is no difference, which is fairly true for CRT and plasma screens. However, viewing angles differ between LCD and front and rear-projection screens. Horizontal ...

A quarter turn is 90° and is called a right angle. A half turn is 180° and is known as a straight angle (or angle on a straight line). A three-quarter turn is 270°. An acute angle is less than ...