# Geometry HELP

posted by
**Ariel**
.

Using coordinate geometry to prove that the diagonals of a square are perpendicular to each other.

Given: Vertices are at A(0,0), B(a,0), C(a,a) and D(0,a) Slope of AC=1; Slope of BD=-1

Type your proof.

(someone plz help cuz i don't understand)