Explain the ray diagram for the image obtained by a concave mirror by considering three rays.

(N/A) The figure shows the ray diagram considering three rays originating from point $A$ of an object $AB$.
$1$. $A$ ray parallel to the principal axis,after reflection,passes through the principal focus $F$.
$2$. $A$ ray passing through the center of curvature $C$ is reflected back along the same path.
$3$. $A$ ray incident at the pole $P$ is reflected at an equal angle with the principal axis.
These three rays intersect at point $A^{\prime}$,which is the image of point $A$. By dropping a perpendicular from $A^{\prime}$ to the principal axis,we get the image $A^{\prime}B^{\prime}$ of the object $AB$. Since rays actually intersect at $A^{\prime}$,the image is real and inverted.