Question

The triangle with vertices at A (-2, 2), B (-8, -1) and C (-8, -1) is reflected about the line y= 2x + 1. Express the coordinates of the reflection of A as an ordered pair.

How do you set this problem up?

Thank you.

A neat way to check your thinking. Draw the system (triangle, line) on a piece of graph paper. Fold the paper along the line. That is reflection.

Now. The math:

http://www.geom.uiuc.edu/docs/reference/CRC-formulas/node9.html

Answer 1

First, if B and C have the same coordinates then we have a line segment not a triangle.