Arcs and sectors
Circles and trigonometry · Stage 3
Recognize the pattern
An arc is the same fraction of circumference as its central angle is of 360°.
Useful ruleθ/360 of circumference/area
Build on: GEO-01
Try it before reading the solution
A circle has radius 6. Find the arc length for a 90° central angle.
This teaching example is original and is not an official SAT question.
Reasoning
(90/360)(2π·6)=3π.
Answer3π
03 · Next step
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Practice questions remain in English, as on the SAT.