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Tangent of a circle

Is a line that intersects a circle at exactly 1 point (point of tangency / contact)

Postulate 1: a tangent line is perp to the radius drawn

To the point of tangency

Postulate 2: is a line is perp to a radius at its outer endpoint then it is a

tangent to the circle

External part of the secant

Part of the secant that forms a segment that joins the outside point to the nearer intersection point

Thm 85: is 2 tangent segment s are drawn to a circle from the external point

Then they are congru

Tangent circles

Crcles that intersect at exactly 1 point

Common tangent to circle

Is a line thangent to 2 circle at the same time

Congruent archs

2 archs are congruent whenever they have the same measure and are parts of the same circle or congruent cirles

In the same circle or congruent cirlces, 3 things will always be equall

Chords, archs and central angles of the same thing

Thm 79: if 2 central angles of a circle(s) are congruent, then

Their intercepted archs are congruent

Thm 80: if 2 arcs of a circle(s) are congruent then the corresponding

Central angles are congruent

Thm 81: if 2 central angles of a circle(s) are congruent them

The corresponding central angles are congruent

Thm 82: if 2 chords of a circle(s) are congruent, then the corresponding

Central angles are congruent

Thm 83: if 2 archs of a circle(s) arecongruent then the corresponding

Chords are congruent

Thm 84: if 2 chords of a circle(s) are congruent, then the corresponding

Arcs are congruent