Math
posted by Courtney .
The measure of an angle formed by two secants intersecting inside the circle equals
a.½ the sum of the intercepted arcs
b.½ the difference of the intercepted arcs
c.½ the measure of the intercepted arc
I need help please!

http://www.cuttheknot.org/Curriculum/Geometry/SecantAngle.shtml
Inside > half the sum