GIVEN: ab perpendicular to BC AND DC PERPENDICULAR TO BCAC = BDPROVE:AB =DC Proofs

Let's take a look at the triangles ABC and DCB

1. angles : B=C=90° because they are right triangles (AB perpendicular to BC and DC perpendicular to BC)

2. AC=BD (given)
3. BC is in common (the two triangles have it, you can say it like BC=BC)

So we proved that by SAS(side angle side), the triangles are congruent ABC= DCB

Since the triangles are congrueny, all their sides are equal so we can say that AB=DC