Let’s try to find out the answer to the questions give below studying the figure beside.

i. Let’s write the names of two complementary angles.

ii. Let’s write the names of two supplementary angles.

iii. Let’s write the names of two vertically opposite angles.

i. Complementary angles is defined as those pairs of angles which sum up to 90°.

In the above figure, OM is the angle bisector.

Ray OD is perpendicular to line AB.

So ∠AOM + ∠MOD = 90°.

Hence ∠AOM and ∠MOD are two complementary angles.

ii. Supplementary angles can be defined as those pairs of angles which sum up to 180°.

In the above figure,

∠AOD = 90° = ∠BOD ………. (as OD is perpendicular to line AB)

So ∠AOD + ∠BOD = 180°.

Similarly ray CO is perpendicular to line AB.

So ∠AOC + ∠BOC = 180°

So, the two pairs of supplementary angles are ∠AOD & ∠BOD and ∠AOC & ∠BOC

iii. In the above figure,

AB and CD are two straight lines intersecting at point O.

∠AOD is lying opposite to ∠BOC.

Similarly, ∠BOD is lying opposite to ∠AOC.

Hence ∠AOD and ∠BOC form the first pair of vertically opposite angles.

∠AOC and ∠BOD forms the second pair of vertically opposite angles.