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Arc Length. Warm Up!. What is the formula for finding the circumference C of a circle with radius r? Find the measure of the circumference of a circle with radius 14.3 inches?. Exact Measure. Circumference. EX : What is the exact measure of the circumference?.
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Warm Up! • What is the formula for finding the circumference C of a circle with radius r? • Find the measure of the circumference of a circle with radius 14.3 inches?
Exact Measure Circumference EX: What is the exact measure of the circumference? Writing your answer in terms of π 14.3 in.
What is Circumference? Circumference The entire distance around a circle
Arc Length of a Circle piece portion a segment of the circumference of a circle part section
Start at the point (1, 0) and walk around the circle a distance of radians. We will arrive at a point . The distance traveled, t, is shown in red. At the right of the circle is a red line segment that ends in a blue point that is exactly the same length as the red arc ending in the blue point. What is the distance that we walked?
Arc Length Corollary? Is the ratio of the arc length to the circumference is equal to the ratio of the angle to 360º * * Arc Length = Radians Radius =
Arc Length = Radians Radius = • Arc length of a circle in radians In the Unit Circle, the arc length = theta(in radians). Why?
Find the length of the arc formed by theta: • How long is the arc subtended by an angle of radians on a circle of radius 20 cm? • How long is the arc subtended by an angle of radians on a circle of radius 5 cm? Find the radian measure for the following: Find the radian measure a circle of radius 15 inches an angle intercepts an arc of 32 inches?
Find the radius for an angle measuring 1.71 radians intercepting an arc with length 12 in. Text your answer choice to me! • 7 in • 14 in • 4.47 in • 10 in
Given a clock with minute hand 6 cm long how far does the tip of the hand move from 12:05 to 12:20? Practice Time!
Guided Practice Complete How Do You Find Arc Length?
A 90º B Example 1 14 cm How long is the arc subtended by an angle of on a circle of radius 14 cm? =7radians
A Arc Length = Radians Radius B Example 2 20 m Arc Length = How long is the arc subtended by an angle of radians on a circle of radius 20 cm? =35radians
A Arc Length = Radians Radius B Example 3 20 m Arc Length = What is the radian measure in a circle of radius 15 inches when an angle intercepts an arc of 32 inches? =35radians
Practice Time! p. 226 (1-10, 17-19) Show ALL Work for Credit!!