Question

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

1. Obtuse vertically opposite angles
2. Adjacent complementary angles
3. Equal supplementary angles
4. Unequal supplementary angles
5. Adjacent angles that do not form a linear pair

Answer 1

(i) Obtuse vertically opposite angles means greater than $90\degree$ and equal $∠AOD = ∠BOC$.

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(ii) Adjacent complementary angles means angles have common vertex, common arm, non-common arms are on either side of common arm and sum of angles is $90\degree$.

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(iii) Equal supplementary angles means sum of angles is $180°$ and supplement angles are equal.

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(iv) Unequal supplementary angles means sum of angles is 180° and supplement angles are unequal. i.e., $∠AOE, ∠EOC; ∠AOD, ∠DOC$ and $∠AOB, ∠BOC$

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(v) Adjacent angles that do not form a linear pair mean, angles have common ray but the angles in a linear pair are not supplementary. i.e., $∠AOB, ∠AOE; ∠AOE, ∠EOD$ and $∠EOD, ∠COD$