# Ex.5.1 Q14 Lines and Angles - NCERT Maths Class 7

## Question

In the adjoining figure, name the following pairs of angles:

(i) Obtuse vertically opposite angles.

(ii) Adjacent complementary angles

(iii) Equal supplementary angles.

(iv) Unequal supplementary angles.

(v) Adjacent angles that do not form a linear pair.

## Text Solution

**Steps:**

(i) Obtuse vertically opposite angles mean angles greater than \(90^\circ\) and are equal

\(\angle AOD = \angle BOC\)

(ii) Adjacent complementary angles have common vertex and common arm, non - common arms are on either sides of common arm and their sum is \(90^\circ.\)

\(\angle EOA \,\,{\text {and}} \,\,\angle AOB\) are adjacent complementary angles.

(iii) Equal supplementary angles have sum of angles \(180^\circ\) and supplementary angles are equal.

\(\angle EOB\,\,{\text {and} }\,\,\angle EOD\)

(iv) Unequal supplementary angles have sum of angles \(180^\circ\) and supplementary angles are unequal.

\(\angle EOA\) and \(\angle EOC.\)

(v) Adjacent angles that do not form a linear pair. (Linear pairs are adjacent angles whose sum is equal to \(180^\circ\)).

\(\angle AOB\) and \(\angle AOE;\) \(\angle AOE\) and \(\angle EOD;\) \(\angle EOD\) and \(\angle COD\)