I actually can't figure this one out. I mean, it's obvious from looking at it that they're equal, and probably you are going to use the Side-Angle-Side congruence property (er, postulate), but I can't figure out how to get that angle. There's probably a nice easy property about triangles inscribed in circles, but I can't remember it for the life of me.
Edit: Oh, got it. (looked up some properties)
In a circle, or congruent circles, congruent chords have congruent arcs. (and converse)
In a circle, or in congruent circles, two arcs are congruent if and only if the corresponding chords are congruent.
chord BC â‰… chord DC, so
arc BC â‰… arc DC, so
âˆ BAC â‰… âˆ DAC