What is a reflex angle?
(a). less than 90°
(b). greater than 90°
(c). less than 180°
(d). greater than 180°

Hint: An angle is the measure of rotation of one ray from another, both having a common point. The rays subtract two angles of either side of them. A reflex angle is the largest angle between the two rays.

Complete Step-by-Step solution:
In geometry, an angle can be defined as the figure formed by two rays meeting at a common endpoint. Angles are measured in degrees and radians.
There are different types of angles, such as acute angle, right angle, obtuse angle, straight angle, reflex angle, and complete angle.
An acute angle is the smaller angle between two rays whose measure is less than 90°.
A right angle is an angle whose measure equals exactly 90°.
An obtuse angle is also the smaller angle formed between the arms of the rays but its measure is greater than 90° and less than 180°.
The reflex angle is the larger angle between two rays and its measure ranges from 180° to 360°. It is also obtained by adding 180° to the acute angle, right angle, or obtuse angle.
The complete angle is the angle which measures 360° and represents a full rotation. It is a special kind of reflex angle.

Hence, the correct answer is option (d).

Note: You might choose greater than 90° assuming that even angles greater than 180° are greater than 90° but it is wrong. Even 120° is greater than 90° but it is not a reflex angle.