FiveMinute Check over Lesson 10 1 CCSS ThenNow

Five-Minute Check (over Lesson 10– 1) CCSS Then/Now New Vocabulary Key Concept: Sum of Central Angles Example 1: Find Measures of Central Angles Key Concept: Arcs and Arc Measure Example 2: Classify Arcs and Find Arc Measures Theorem 10. 1 Example 3: Real-World Example: Find Arc Measures in Circle Graphs Postulate 10. 1: Arc Addition Postulate Example 4: Use Arc Addition to Find Measures of Arcs Key Concept: Arc Length Example 5: Find Arc Length

Over Lesson 10– 1 Name a radius. A. B. C. D.

Over Lesson 10– 1 Name a chord. ___ A. LF ___ B. MF ___ C. OM ___ D. NF

Over Lesson 10– 1 Name a diameter. ____ A. OM ___ B. OL ___ C. NF ____ D. MF

Over Lesson 10– 1 Refer to the figure. Find BC. A. 2 B. 3 C. 4 D. 5

Over Lesson 10– 1 Refer to the figure. Find DE. A. 9 B. 11 C. 13 D. 15

Over Lesson 10– 1 Find the length of the radius of the circle. A. 6. 5 in. B. 10. 9 in. C. 13 in. D. 17 in.

Content Standards G. C. 2 Identify and describe relationships among inscribed angles, radii, and chords. G. C. 5 Derive using similarity the fact that the length of the arc intercepted by an angle is proportional to the radius, and define the radian measure of the angle as the constant of proportionality; derive the formula for the area of a sector. Mathematical Practices 6 Attend to precision. 4 Model with mathematics.

You measured angles and identified congruent angles. • Identify central angles, major arcs, minor arcs, and semicircles, and find their measures. • Find arc lengths.

• central angle • arc • minor arc • major arc • semicircle • congruent arcs • adjacent arcs • arc length

Find Measures of Central Angles Find the value of x.

Find Measures of Central Angles The sum of the measures of Substitution Simplify. Add 2 to each side. Divide each side by 26. Answer: x = 7

Find the value of x. A. 9 B. 10 C. 11 D. 65

Classify Arcs and Find Arc Measures Answer:

Classify Arcs and Find Arc Measures

Classify Arcs and Find Arc Measures Answer:

Classify Arcs and Find Arc Measures Answer:

A. B. C. D.

A. B. C. D.

A. B. C. D.

Find Arc Measures in Circle Graphs m LPK = 0. 21(360) = 75. 6 Answer: Find 21% of 360. Simplify.

Find Arc Measures in Circle Graphs

Find Arc Measures in Circle Graphs Sum of arcs in a circle is 360. Substitution Simplify. Answer:

A. 124. 3 B. 140. 4 C. 155. 6 D. 165. 9

A. 273. 6 B. 240. 5 C. 215. 7 D. 201. 4

Use Arc Addition to Find Measures of Arcs .

Use Arc Addition to Find Measures of Arcs Arc Addition Postulate = 58 + 32 = 90 Answer: Substitution

Use Arc Addition to Find Measures of Arcs

Use Arc Addition to Find Measures of Arcs Arc Addition Postulate = m IMJ + m JMK = 90 + 58 = 148 Answer: Substitution

A. 180 B. 90 C. 52 D. 38

A. 52 B. 90 C. 142 D. 180

Find Arc Length Equation Substitution cm Answer: Use a calculator.

Find Arc Length Equation Substitution Use a calculator. Answer:

Find Arc Length Equation Substitution Use a calculator. Answer:

A. 3. 56 cm B. 3. 77 cm C. 3. 98 cm D. 4. 21 cm

A. 36. 56 cm B. 37. 79 cm C. 38. 61 cm D. 40. 21 cm

A. 32. 99 cm B. 33. 59 cm C. 33. 89 cm D. 34. 61 cm