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13 terms

learning vocab terms, and properties about angles in circles.

Chord

A line that passes through the circle, but does not pass through the center.

Diameter

a line that passes through the center of the circle.

Radius

a line that touches the center of the circle and the edge of the circle.

Semicircle

half a circle; 180 degress

Central Angle

the vertx of the angle measure is in the center of the circle

Inscribed Angle

the vertex of the measure angle is on the edge of the circle. The vertex will be doubled to find the measure of the arc, or the central angle. Any two vertextes may be placed inside the circle and they will alway share the same arc measure if the endpoints are the same.

Angles Inscribed in a Semicircle

will always be a 90 degress, since the arc is 180 degress.

Intersecting Chords

When two chords cross over each other, you'll be left with four ''legs'' multiply the opposite legs together to find x. set up a porportion.

Congruent Chords

the arcs will be the same. the central angles are congruent.

Secant

a line that intersects the circle at two points

Tangent

touches the circle at one point, will nevr e inside the circle, it will only ever touch the outside of the circle. The point of tangency. a radius touching a tangent will always make a 90 degress angle.

Inscribed Quadrilaterals

opposite angles indcribed in a circle are always have a sum of 180.

Parelle Lines Inside a Circle

they can be diffrent lengths, but will have congruent arcs.