Answer:
Option (4)
Step-by-step explanation:
By the Angle of intersecting secants,
"If two lines intersect outside a circle, then the measure of the angle between these lines or secants will be one half of the difference between the intercepted arcs."
From the picture attached,
Angle between the secants = ∠1
Measure of intercepted arcs are a° and b°.
By this theorem,
m∠1 = [tex]\frac{1}{2}(a-b)[/tex]
Option (4) will be the answer.
