The measure of ADB is 110°.
Solution:
m(ar BDC) = 70°
The measure of the central angle is congruent to the measure of the intercepted arc.
⇒ m∠BDC = m(ar BDC)
⇒ m∠BDC = 70°
Sum of the adjacent angles in a straight line = 180°
⇒ m∠ADB + m∠BDC = 180°
⇒ m∠ADB + 70° = 180°
Subtract 70° from both sides.
⇒ m∠ADB = 110°
m(ar ADB) = m∠ADB)
m(ar ADB) = 110°
Hence the measure of ADB is 110°.
