You can see from the diagram that one of the angles is 100º. You can also see that the missing angle is greater than 100º. It is a reflex angle.

The angle in the following diagram is a reflex angle. The line turns through more than two right angles, but less than three right angles, so is between \(180^\circ\) and \(270^\circ\).

Proximity diagrams have applications in most areas of science and engineering. ... they have boundaries made up of straight line segments and all corners have internal angles less than 180 degrees.