Question

1.
Find the length of an arc of a circle which
subtends an angle of 144º at the centre, if the
radius of the circle is 5 cm.​

Answer 1

Given

⇒ Length of an arc =20πcm

⇒ θ=144

o

⇒ Length of an arc =

360

o

θ

(2πr)

Where, θ is angle subtended at a center.

2πr is circumference of a circle.

∴ 20π=

360

o

144

o

×2πr

∴ r=

4

100

=25cm