Question 1

Match the following:

(i) Straight angle (a) less than one-fourth a revolution
(ii) Right angle (b) more than half a revolution
(iii) Acute angle (c) half of a revolution
(iv) Obtuse angle (d) one-fourth a revolution
(v) Reflex angle (e) between $\frac{1}{4}$ and $\frac{1}{2}$ of a revolution
(f) One complete revolution

Turning by two straight angles or four right angles in the same direction makes a full turn. This one complete turn is called one revolution. The angle for one revolution is a complete angle.

An angle smaller than a right angle is called an acute angle.

If an angle is larger than a right angle but less than a straight angle, it is called an obtuse angle.

A reflex angle is larger than a straight angle.

(i) $\to$ (c)
(ii) $\to$ (d)
(iii) $\to$ (a)
(iv) $\to$ (e)
(v) $\to$ (b)