The sum of all conjugate angles is degrees.

In the given figure, $\mathbf{\angle }1\mathbf{}$ and $\mathbf{}\mathbf{\angle }2\mathbf{}$ are supplementary angles. If $\mathit{\angle }1$ is decreased, what changes should take place in $\mathit{\angle }2$ so that both the angles still remain supplementary.

Look at the following figures and write the name of the vertex of the angle :

In the given figure, write another name for $\angle 1$.

Look at the following figures and write the names of arms of the angle :

Look at the following figures and write the name of the vertex of the angle :

In the given figure, list the points which are in the interior of $\angle AOB$

The vertex of an angle lies:

Name the vertex and the arms of $\angle ABC$.