I. True or False. Write TRUE if the statement is correct and FALSE if the statement is incorrect.
_________1. A line coplanar with the circle and intersects it in one and only one point is tangent to a circle.
_________2. An external secant segment is a part of a secant segment that is inside a circle.
_________3. When a secant and a tangent intersect at the point of tangency, the measure of each angle formed is one-half the measure of its intercepted arc.
_________4. Sector of a circle is the region bounded by an arc of the circle and the two radii to the endpoint of the arc.
_________5. If two tangents intersect in the interior of a circle, the measure of an angle formed is one-half the sum of the measures of the arcs intercepted by the angle and its vertical angle.
_________6. If a line is perpendicular to a radius of a circle at its endpoint that is on the circle, then the line is tangent to the circle.
_________7. If two secant intersects int the exterior of a circle, then the measure of the angle formed is one-half the positive difference of the measures of the intercepted arcs. ​