Warm Up April 24th 1. What is the formula for the

inscribed angle?

2. What is the formula for a vector outside the circle?

EOCT Week 14 #4

Circumference & Arc Length

of Circles

CircumferenceThe distance around a circle

orC 2 r

C d

Circumference

Find the EXACT circumference.

28 ft1.r = 14 feet

2.d = 15 miles15 miles

Ex 3 and 4: Find the circumference. Round to the nearest tenths.

89.8 mm 103.7 yd

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

r2 C C 2 3

Arc LengthThe distance along the curved line

making the arc (NOT a degree amount)

Arc Length

measure of arcArc Length 2

360r

Ex 6. Find the Arc LengthRound to the nearest hundredths

8m

70

9.77 m

measure of arcArc Length 2

360r

Ex 7. Find the Arc Length Round to the nearest hundredths

12 in

110

23.04 in

measure of arcArc Length 2

360r

Ex 8. Find the exact Arc Length.

10 in3

measure of arcArc Length 2

360r

Area of a Circle

Ex 9. Find the exact area of the circle.

Ex 10. Find the exact area of the circle.

Area of a sector of a circle

Ex 11. Find the exact area of the sector of the circle.

Ex 12. Find the exact area of the sector of the circle.

Area of a segment

Ex 13. Find the area of the segment.

Ex 14. Find the area of the segment.

Radian Measure of a

Circleanother way to measure

angles!

How to convert from …

• Degrees to Radians: • Radians to Degrees:

180multiply by 180multiply by

Mode – RADType degreesMath – DMS – 1:OR Angle – 1: enter

Mode – DEGType radiansMath – DMS – 4:OR Angle – 4: enter

Arc Length Homework11 problems