12 multiple-choice questions, progressively harder.
Find the length of the selected 105∘105^\circ105∘ arc in a circle of radius 161616 cm.
Solution
Correct answer: C
Use the selected degree fraction of the circumference.
A selected arc is 18π18\pi18π cm long and has central turn 3π4\tfrac{3\pi}{4}43π radians. Find the circle's radius.
Correct answer: A
Divide the arc length by its radian measure.
A circle has radius 151515 cm. The minor central angle between OAOAOA and OBOBOB is 132∘132^\circ132∘. Find the length of the major arc with endpoints AAA and BBB.
Correct answer: D
The major route uses the part of a full turn left after the minor turn.
In the same circle, selected arcs AAA and BBB have central turns π/5\pi/5π/5 and 2π/32\pi/32π/3 radians respectively. What is the ratio of length AAA to length BBB?
Correct answer: B
Both arc lengths contain the same positive radius, so it cancels from their ratio.
One selected arc has radius 111111 cm and central turn 4/74/74/7 radian. Another has radius 222222 cm and central turn 2/72/72/7 radian. How do their lengths compare?
The doubled radius and halved turn offset each other.
Convert 294∘294^\circ294∘ to radians exactly.
Use pi radians for every 180 degrees.
Convert 13π15\tfrac{13\pi}{15}1513π radians to degrees.
The factor of pi cancels during conversion.
A circle has circumference 30π30\pi30π cm. Find the length of a selected arc with central turn 11π/611\pi/611π/6 radians.
Recover the radius from the circumference, then multiply by the selected turn.
A circle has radius 7.57.57.5 cm. Find the length of a selected arc with central turn 2.22.22.2 radians.
A radian measure may be a decimal without containing pi.
A circle has radius 131313 cm. What is the length along its selected minor arc of central turn π/3\pi/3π/3 radians?
Follow the curved arc rather than the chord joining its endpoints.
In a circle of radius 888 cm, the minor arc from AAA to BBB is 10π/310\pi/310π/3 cm long. Find the length of the major arc with the same endpoints.
The two routes together make the circumference.
A selected arc in a circle of radius 222222 cm occupies 3/83/83/8 of a full turn. Which pair gives its radian measure and arc length?
Use three eighths of a full radian turn, then apply that same fraction to the circumference.
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