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Geometry Arcs and chords. Warm Up. 90° 9. Arcs and Chords. A center angle is an angle whose vertex is the center of a circle. An arc is an unbroken part of a circle consisting of two points called the end points and all the points on the circle between them. A. A. B. B. C. C.
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GeometryArcs and chords CONFIDENTIAL
Warm Up • 90° • 9 CONFIDENTIAL
Arcs and Chords A center angle is an angle whose vertex is the center of a circle. An arc is an unbroken part of a circle consisting of two points called the end points and all the points on the circle between them. CONFIDENTIAL
A A B B C C Arcs and Their Measure CONFIDENTIAL
A Rock 25% Other 26% M H B Jazz 13% Rap 13% G F Classical 3% C E Pop 13% D R & B 11% Country 10% The circle graph shows the types of music sold during one week at a music store. Find CONFIDENTIAL
Classical 3% Rock 25% Other 26% M H B Jazz 13% Rap 13% G F C E Pop 13% D R & B 11% Country 10% Now you try Use the graph to find each of the following. • 108° • 270° • 36° CONFIDENTIAL
S T R Adjacent arcs are arcs of the same circle that intersect at exactly one point. and are adjacent arcs. CONFIDENTIAL
S T R Arc Addition Postulate The measures of an arc formed by two adjacent arcs is the sum of the measures of the two arcs. CONFIDENTIAL
Using the Arc Addition Postulate CONFIDENTIAL
Now you try! Find each measure. • 140° • 250° CONFIDENTIAL
With in a circle or congruent circles, congruent arcs are two arcs that have the same measure. In the figure, CONFIDENTIAL
The converses of the parts of previous theorems are also true. For example, with PART A, congruent chords have congruent central angles CONFIDENTIAL
PART A Proof: CONFIDENTIAL
Applying Congruent Angles, Arcs, and Chords Find each measure. 1) CONFIDENTIAL
2) CONFIDENTIAL
Now you try! • 12 • 100° Find each measure 1) 2) CONFIDENTIAL
Using Radii and Chords CONFIDENTIAL
Now you try! 4) Find QR to the nearest tenth. 4) 46.6 CONFIDENTIAL
Now some problems for you to practice. CONFIDENTIAL
ASSESSMENT 1) The circle graph shows how a typical household spends money on energy. Find each of the following. • 198° • 19.8° • 61.2° • 36 • 39.6 • 324 CONFIDENTIAL
Find each measure. 2) 139° 3) 270° CONFIDENTIAL
4) 108° 5) 210° CONFIDENTIAL
6) 24 CONFIDENTIAL
7) 135° CONFIDENTIAL
REVIEW A A B B C C Arcs and Chords Arcs and Their Measure CONFIDENTIAL
A Rock 25% Other 26% M H B Jazz 13% Rap 13% G F Classical 3% C E Pop 13% D R & B 11% Country 10% The circle graph shows the types of music sold during one week at a music store. Find CONFIDENTIAL
S T R Adjacent arcs are arcs of the same circle that intersect at exactly one point. and are adjacent arcs. CONFIDENTIAL
S T R Arc Addition Postulate The measures of an arc formed by two adjacent arcs is the sum of the measures of the two arcs. CONFIDENTIAL
Using the Arc Addition Postulate CONFIDENTIAL
With in a circle or congruent circles, congruent arcs are two arcs that have the same measure. In the figure, CONFIDENTIAL
PART A Proof: CONFIDENTIAL
Applying Congruent Angles, Arcs, and Chords Find each measure. 1) CONFIDENTIAL
2) CONFIDENTIAL
Using Radii and Chords CONFIDENTIAL
You did a great job today! CONFIDENTIAL