A circle has a radius of 9 cm. A central angle measures 315 degrees. ?
Determine the arc lenth subtended by two radii making the central angle. Round your answer to the nearest tenth of a centimeter.
5 Answers
- sepiaLv 71 year ago
A circle has a radius of 9 cm.
A central angle measures 315 degrees.
Determine the arc length subtended by two radii making the central angle.
2 pi * 9 (315/360) cm = 49.4800843 cm or
49.5 cm (rounded to the nearest tenth of a centimeter).
- Anonymous1 year ago
315 / 360 * pi * radius
- PuzzlingLv 71 year ago
What's the circumference of a full circle with a 9 cm radius?
C = 2πr
C = 2π*9
C = 18π cm
But you don't want a full 360°, you just want 315°. So multiply by 315/360. We can reduce that fraction if you like by dividing top and bottom by 45.
315/360
= 7/8
So take 7/8 of the full circumference:
arc = 7/8 * 18π cm
arc = 7/4 * 9π cm
arc = 63π / 4
arc ≈ 49.48 cm
Answer (to the nearest tenth of a centimeter)
~49.5 cm
- stanschimLv 71 year ago
s = rθ, where θ is measured in radians.
θ = (315 / 180)π radians = 7π/4 radians
s = 9(7π/4) = 63π/4 = 49.5 cm
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- 1 year ago
2 * pi * 9 * (315/360) =>
18 * pi * (7/8) =>
9 * pi * 7 / 4 =>
63 * pi / 4 =>
49.4800...
49.5
Or
(63/4) * pi =>
(63/4) * (22/7), roughly
(63/7) * (22/4) =>
9 * 11/2 =>
99/2 =>
49.5