7.0 Reflection of a point about a line

7.1 Reflection with respect to $X-$axis
7.2 Reflection with respect to $Y-$axis
7.3 Reflection with respect to Origin
7.4 Reflection with respect to the line $x=a$
7.5 Reflection with respect to the line $y=b$
7.6 Reflection with respect to the line $y=x$

In order to find the reflection of a point $P({x_1},{y_1})$ about a line, first of all, find the foot of perpendicular, say $M$, from a

point to a line and use fact that $M$ is the midpoint of a line joining $P$ and $Q$, where $Q$ is the reflection of point about a line.

Let us assume the coordinates of point $Q$ be $({x_2},{y_2})$, then the coordinates of $M$ using mid-point formula is $$M \equiv (\frac{{{x_1} + {x_2}}}{2},\frac{{{y_1} + {y_2}}}{2})$$