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Warm up: Solve for x . 1.). 124 ◦. 2.). 70 ◦. x. 18 ◦. x. 4.). 3.). 260 ◦. x. 20 ◦. 110 ◦. x. Questions over hw ?. Daily Check. Circumference & Arc Length of Circles. Circumference. The distance around a circle. Circumference. or. r = 14 feet d = 15 miles.
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Warm up: Solve for x 1.) 124◦ 2.) 70◦ x 18◦ x 4.) 3.) 260◦ x 20◦ 110◦ x
Circumference The distance around a circle
r = 14 feet d = 15 miles Find the EXACT circumference.
33 yd Ex 3 and 4: Find the circumference. Round to the nearest tenths. 14.3 mm
5. A circular flower garden has a radius of 3 feet. Find the circumference of the garden to the nearest hundredths. C = 18.85 ft
Arc Length The distance along the curved line making the arc (NOT a degree amount)
Ex 6. Find the Arc LengthRound to the nearest hundredths 8m 70
Ex 7. Find the Arc Length Round to the nearest hundredths 12 in 110
Ex 9. What happens to the arc length if the radius were to be doubled? Halved?
Classwork Practice from Notes Page
Area of Circles & Sectors
2 Types of Answers Rounded • Type the Pi button on your calculator • Toggle your answer • Do NOT write Pi in your answer Exact • Pi will be in your answer
r Area A= pr2 The amount of space occupied.
r = 29 feet • d = 44 miles Find the EXACT area.
Find the area. Round to the nearest tenths. 53 cm 7.6 yd
Example 3 If S has a diameter of 10 inches, find the area of the circle to the nearest hundredths. A = 78.54 in2
Sector the region bounded by two radii of the circle and their intercepted arc.
R 6 cm Example 4 60 Q Find the area of the sectorto the nearest hundredths. A 18.85 cm2
6 cm 7 cm R Q 120 Example 5 Find the exact area of the sector.
Example 6 Find the area of a sector with a central angle of 45° if the diameter of the circle is 12 inches. Round to the nearest hundredths. A 14.14 in2
Example 7 A spinner is divided into 12 equal sections and the radius of the spinner is 4 inches. Every other section is shaded. Find the exact total area of the shaded region on the spinner. A = 8 in2
Homework 9 Problems