Inscribed angle in a circle

Author:
Mr. Santos
Topic:
Circle

Inscribed angle in a circle

G.GCI.2* Identify and describe relationships among inscribed angles, radii, and chords; among inscribed angles, central angles, and circumscribed angles; and between radii and tangents to circles.

Moving point B and point C. What relationship do you see between the angle BAC and the subtended arc?

Can you derive a formula from the relationship?