Suppose we wanna find distance between the origin & a point on 2D Plane:

Origin: $(x1,y1) = (0,0)$ Point: $(x2,y2)=(x,y)$

Euclidean distance formula: The Euclidean distance between two points (x1,y1) and (x2,y2) is given by:

d = \sqrt{(x_2^2 - x_1 ^ 2) + (y_2^2 - y_1 ^ 2) }

Substitute the coordinates:

d = \sqrt{(x^2) + (y^2) }