4b: Measuring Angles and ArcsA central angle of a circle is an

angle with a vertex at the circle center. Its sides contain two radii of the circle.

4b: Measuring Angles and ArcsThe sum of the central angles of

a circle are 360º.

4b: Measuring Angles and ArcsExample:Find the value of x.

4b: Measuring Angles and ArcsExample:Find the value of x.

4b: Measuring Angles and ArcsAn arc is a portion of a circle

defined by two endpoints.

4b: Measuring Angles and Arcs

4b: Measuring Angles and Arcs

4b: Measuring Angles and ArcsExample:

4b: Measuring Angles and ArcsCongruent arcs are arcs in the

same or congruent circles that have the same measure.

4b: Measuring Angles and Arcs

4b: Measuring Angles and ArcsAdjacent arcs in a circle have

exactly one point in common.

4b: Measuring Angles and ArcsExample:

4b: Measuring Angles and ArcsArc Length is the distance between

the endpoints along an arc measured in linear units.

4b: Measuring Angles and Arcs

4b: Measuring Angles and Arcs

4b: Measuring Angles and ArcsHomework:Page 710 – 711, #12 – 23 all, 26 – 38 all.