Answer:
mADC = 220°
Step-by-step explanation:
In the given diagram AB and BC are tangents to the given circle O. We have to find the measure of arc ADC.
By theorem of tangents and arcs.
m∠ABC = [tex]\frac{1}{2}[/tex] [m ADC- m AC ]
Since it is given in the question
∠ABC = 40 & AC = 140°
Therefore, 40 = [tex]\frac{1}{2}[/tex] [ m ADC - 140 ]
40 × 2 = m ADC - 140
80 + 140 = m ADC
mADC = 220°
