Answer:
✏ANSWER:
[tex]m < ABC = 40°[/tex]
✏SOLUTION:
The central Angle is equal twice the inscribed Angle of the same arc
[tex]so \: \: m < 1 = \frac{1}{2}m AD = \frac{1}{2} \times 160 = 80°[/tex]
[tex]m < 2 = \frac{1}{2} mEF = \frac{1}{2} \times 80 = 40 °[/tex]
[tex] < 1 + < 3 = 180°[/tex]
[tex]( < 2 + <ABC ) + < 3 = 180°[/tex]
[tex]so \: \: < 1 = < 2 + < ABC[/tex]
[tex]80° = 40° + < ABC[/tex]
[tex] < ABC = 40°[/tex]
