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10 Cards in this Set
- Front
- Back
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The radius of a circle is 4 feet. What is the length of 225° arc?
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The formula for the length of an arc is l=(m/360)(C), so first we need to find the circumference.
C=2πr C=2π(4) C=8π. Now, to find the length of the arc. l=(m/360)(C) l=(225/350)(8π) l=0.625(8π) l=5π |
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The diameter of a cricle is 8 feet. What is the length of 180° arc?
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C=2πr
C=2π(4) C=8π l=(m/360)(C) l=(180/360)(8π) l=(1/2)(8π) l=4π |
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The radius of a circle is 6 feet. What is the length of 60° arc?
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C=2πr
C=2π(6) C=12π l=(m/360)(C) l=(60/360)(12π) l=(1/6)(12π) l=2π |
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The radius of a circle is 4 miles. What is the area of a sector bounded by a 130° arc?
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The formula for the area of a sector is K=(m/360)(A), where K is the area of the sector and, m is the measure in degrees of the arc bounding the sector and A is the area of the circle.
First we must find the area of the circle. A=πr² A=π(4)² A=16π sq miles Now we must find the area of the sector. K=(m/360)(A) K=130/360(16π) K=5π/9 square miles |
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The radius of a circle is 12 miles. What is the area of a sector bounded by a 240° arc?
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K=(m/360)(A)
A=πr² A=π(12)² A=144π sq miles K=(m/360)(A) K=(240/360)(144π) K=96π square miles |
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The radius of a circle is 9 miles. What is the area of a sector bounded by a 30° arc?
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K=(m/360)(A)
A=πr² A=π(9)² A=81π K=(m/360)(A) K=(30/360)(81π) K=27π/4 sq miles |
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Convert 2π/5 radians to degrees.
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(2π/5)(180/π)=360π/5π= 72°
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Convert 32° to radians.
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(32)(π/180)=8π/45 radians
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Convert 3π/5 radians to degrees.
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(3π/6)(180/π)=540π/6π=90°
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The length of the arc intercepted by an angle is ____________ to the radius.
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The length of the arc intercepted by an angle is proportional to the radius.
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