Adjacent angles

Adjacent angles are two angles that have

• a common vertex;
• a common arm; and
• the non-common arm are on either side of the common arm.

∠AXBand ∠BXC are adjacent angles. Adjacent angles have a common arm but no common interior points.

In above figure X is the common vertex, XB is the common arm.

In fig 1 and fig 2 angle 1 and angle 2 are adjacent, but in fig 3 they are not adjacent to each other/p>

Fig A:

• They are adjacent angles.
• They share the vertex and side.

Fig B:

• not adjacent angles.
• They share the vertex but not a side.

Fig C:

• not adjacent angles.
• They only share the side but not the vertex.

Adjacent angles can be complement to each other.( sum of the angles = 90?)

Adjacent angles can be supplement to each other.(sum of the angles =180?). In this case the angles are in linear pair.

Answer the following;

• From the given figure identify the adjacent angles.

  

• How many adjacent angles are there in the following figure?