Answer:
a) 5
Step-by-step explanation:
If you are given two secants intersecting outside of the circle we use the following formula:
[tex]m \angle 1=\frac{1}{2}(20-10)\\\\m\angle1=\frac{10}{2}=5[/tex]
Answer: 5
sense we already got 19 we just need to divide by to so, 5
