(i) Obtuse vertically opposite angles means greater than \(90\degree\) and equal \(∠AOD = ∠BOC\).
(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 \(90\degree\).
(iii) Equal supplementary angles means sum of angles is \(180°\) and supplement angles are equal.
(iv) Unequal supplementary angles means sum of angles is 180° and supplement angles are unequal. i.e., \(∠AOE, ∠EOC; ∠AOD, ∠DOC\) and \(∠AOB, ∠BOC\)
(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 \(∠EOD, ∠COD\)