## Coordinate Geometry - Triangles, Normals and Distances

Typically in coordinate geometry we are concerned with lines and normals, distances and circles.

We may be of, for the above diagram:

a)Show that AC is perpendicular to AB.

b)Find the distance AB.

a) Gradient of

Gradient of

The product of the gradients is -1 so AC and AB are at right angles.

b)