Question

pairs of
1- vertically opposite angles
2- linear pair​

Answer 1

consider the centre as O

so angle COE =DOF (vertically opposite angles)

the AB and CD are linear pairs

Answer 2

1. Vertically opposite angles

The angles lies on the opposite of the point where two lines intersect, are called vertically opposite angles. Measure of vertically opposite angles is equal. i.e. They are congruent.

Pairs of vertically opposite angles in the figure:

( Let the mid-point, where line intersect be "O" )

• AOC and DOB
• COE and FOD
• EOB and AOF
• AOE and FOB
• EOD and COF
• COB and AOD

2. Linear pair

when two adjacent angle are supplementary, they form a linear pair. supplementary angles add up to 180 degrees, so, it's actually a straight line divided into two angles.

linear pairs in the figure:

• ∠AOC and ∠COB
• ∠AOE and ∠EOD
• ∠AOF and ∠FOB
• ∠AOD and ∠DOB
• ∠COA and ∠AOD
• ∠COF and ∠FOD
• ∠COE and ∠EOD
• ∠COB and ∠BOD
• ∠EOC and ∠COF
• ∠EOA and ∠AOF
• ∠EOB and ∠BOF
• ∠EOD and ∠DOF