We want to find the value of m∠BAC. We know that if two secants or chords intersect inside the circle, then the measure of an angle formed is half the sum of the arcs intercepted by the angle and its vertical angle.
m∠AED = 1/2(mAD+ mCB)
Let's substitute the known values and simplify.
Recall that the Inscribed Angle Theorem states that the measure of an inscribed angle is half the measure of its intercepted arc.
m∠BAC = 1/2(mCB)
Let's substitute mCB for 70^(∘) and simplify.
