5-Minute Check on Lesson 10-2 Transparency 10-3 Click the mouse button or press the Space Bar to display the answers. In ⊙ O, BD is a diameter and m AOD =55°. Find each measure. 1.m COB 2.m DOC 3.m AOB Refer to ⊙ P. Find each measure. 4. mLM 5. mMOL 6. If the measure of an arc is 68°, what is the measure of its central angle? Standardized Test Practice: ACBD 34° 68°102°136° 125° 114° 66° 150° 210° B
Lesson 10-3 Arcs and Chords
Objectives Recognize and use relationships between arcs and chords Recognize and use relationships between arcs and diameters
Vocabulary Inscribed Polygon – all vertices lie on the circle Circumscribed – circle contains all vertices of a polygon
Example 3-2a TESSELLATIONS The rotations of a tessellation can create twelve congruent central angles. Determine whether. Answer: Since the measures of are equal,. Because all of the twelve central angles are congruent, the measure of each angle is 360 12 or 30 Let the center of the circle be A. The measure of PAQ is 5 30 or 150. Then. The measure of SAT is 5 30 or 150. Then.
Example 3-2c ADVERTISING A logo for an advertising campaign is a pentagon that has five congruent central angles. Determine whether. Answer: no
Example 3-3a Circle W has a radius of 10 centimeters. Radius is perpendicular to chord which is 16 centimeters long. If find Since radius is perpendicular to chord Answer: 127
Example 3-3c Circle W has a radius of 10 centimeters. Radius is perpendicular to chord which is 16 centimeters long. Find JL. A radius perpendicular to a chord bisects it. Definition of segment bisector Draw radius
Example 3-3e Use the Pythagorean Theorem to find WJ. Pythagorean Theorem Simplify. Subtract 64 from each side. Take the square root of each side. Segment addition Subtract 6 from each side. Answer: 4
Example 3-3g Answer: 145 Answer: 10 Circle O has a radius of 25 units. Radius is perpendicular to chord which is 40 units long. a. If b. Find CH.
Example 3-4a Chords and are equidistant from the center. If the radius of is 15 and EF = 24, find PR and RH. are equidistant from P, so.
Example 3-4c Draw to form a right triangle. Use the Pythagorean Theorem. Pythagorean Theorem Simplify. Subtract 144 from each side. Take the square root of each side. Answer:
Example 3-4d Answer: Chords and are equidistant from the center of If TX is 39 and XY is 15, find WZ and UV.
Summary & Homework Summary: –The endpoints of a chord are also the endpoints of an arc –Diameters perpendicular to chords bisect chords and intercepted arcs Homework: –pg ; 11-18; 30-33, 52