Classify each of the following marked angles as acute, right, obtuse, straight or a reflex angle :

(i)

(ii)

(iii)

(iv)

(v)

(vi)

(i) The angle is greater than 90° but less than 180°.

∴ It is an obtuse angle.

(ii) The angle is exactly 90°.

∴ It is a right angle.

(iii) The angle is less than 90°.

∴ It is an acute angle.

(iv) The angle is greater than 180° but less than 360°.

∴ It is a reflex angle.

(v) The angle is greater than 90° but less than 180°.

∴ It is an obtuse angle.

(vi) The angle is greater than 180° but less than 360°.

∴ It is a reflex angle.