SemicircleA semicircle is an arc of a circle whose endpoints are the endpoints of the diameter.

The degree measure of a semicircle is 180.

Minor ArcAn arc of a circle that is smaller than a semicircle.

Major ArcAn arc of a circle that is larger than a semicircle.

Central AngleAn angle whose vertex is the center of the circle.

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The measure of the minor arc is the measure of its central angle in degrees.

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The measure of the major arc is 360 minus the measure of its minor arc.

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In the same circle or in congruent circles, two minor arcs are congruent iff their central angles are congruent.

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Two arcs of a circle are adjacent nonoverlapping arcs iff they have exactly one point in common.

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The measure of an arc formed by two adjacent non overlapping arc is the sum of the measures of those two arcs.

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JH

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GH and CF are diameters of concentric circles;

mBHJ=35 and mHJ=mKG

1. Find the measures of the following arcs:

HJ, JG, JK, FE, EC, FCE, HLK.

2. State the relationship between HJ and

FE; between HJ and KG

3. If mBH=20, find mHBL and mLGmBL=20

mJBH=35

A chord corresponds to an arc iff its endpoints are on the circle and on the central angle of the given arc.

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Properties you Properties you have to keep in have to keep in

mind...mind...

Two minor arcs in the same or congruent circles are congruent if their corresponding chords are congruent.

If a diameter of the circle is perpendicular to the chord, then the line bisects the chord and its arc.

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Two chords are equidistant from the center iff they are congruent.

If AG = 4x - 11, BG = 2x - 3, find x and AB

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Given that KUFE,KVDC, KGBA

If CD and EF are equidistant from the center andCD = 5y +2 and EF = 8y - 6, solve for CD + EF.5y+12

ASSIGNMENT

On ¼ sheet of paper, answer page 303, CYU 1-5