10 4-7 Vocab and Concepts Flashcards
tangent
line that intersects circle at exactly ONE point
point of tangency
exact point of intersection between line and circle
common tangent
when a line is tangent to two circles in same plane (external v. internal)
external tangent
tangent is outside both circles
internal tangent
tangent is inside circles
if two segments from the same exterior point are tangent to a circle, then…
those lines are congruent
a line is tangent to a circle if and only if…
the tangent and RADIUS of the circle connected to the point of tangency form a RIGHT
inscribed angle
has a vertex on the circle and is created by two chords
intercepted arc
arc formed by endpoints of chords that form inscribed angle
secant
line that intersects circle at two points
if an angle is inscribed in a circle, then the measure of the angle equals…
one half the measure of its intercepted arc
if two inscribed angles of a circle intercept the SAME ARC (have the same endpoints) then
the angles are congruent
an inscribed angle of a triangle intercepts a diameter or semicircle if and only if…
i.e endpoints are on semicircle means that the angle is
the angle is a right angle
if a quadrilateral is inscribed in a circle, then
the opposite angles are supplementary
if a secant and tangent intersect at the point of tangency, then the measure of each angle formed is
one half the measure of the intercepted arc
