Reflection in the Line y = x

Reflection in the Line y = x

How to solve the reflection in the line y = x problems: formula, example, and its solution.

Formula

The image of a point (x, y), whose image is under a reflection in the line y = x, is (y, x).

The image of a point (x, y),
whose image is under a reflection in the line y = x,
is (y, x).

Example

Triangle ABC has vertices A(4, 1), B(7, 3), and C(5, -2). Its image is under a reflection in the line y = x. Find the coordinates of the vertices of the image.

Reflection in the line y = x:
(x, y) → (y, x)