Foot of Perpendicular from a Point to a Line

Foot of Perpendicular from a Point to a Line

## Formula

For point $$(x_1,y_1)$$ and line:

$$Ax+By+C=0$$

the foot of perpendicular is:

$$\left(x_1-\frac{A(Ax_1+By_1+C)}{A^2+B^2},y_1-\frac{B(Ax_1+By_1+C)}{A^2+B^2}\right)$$

## Usage

- Used to find the exact point on the line where the perpendicular from a given point meets the line.