Question

The radius of the sector is 21 cm and its central angle is 120 degree then the the length of the arc of a circle is

Answer 1

▒▒ Given ▒▒

In a given circle,

The radius of the sector is 21 cm and its central angle is 120°.

• r = 21 cm
• θ = 120°

▒▒ To Find ▒▒

The length of the arc of a circle.

▒▒ Solution ▒▒

$\boxed{\bf{Length\ of\ the\ arc =\frac{\theta}{360^\circ} \times 2\pi r}}$

→ L = 120°/360° × 2π(21)

→ L = 1/3 × 2 × 22/7 × 21

→ L = 1/3 × 2 × 22 × 3

→ L = 2 × 22

→ L = 44 cm

Therefore, the length of the arc of the circle is 44 cm.

Answer 2

$\underline{\underline{\sf\bf \bigstar ANSWER \bigstar \\}}$

Given ,

Radius of sector , r = 21 cm

Central angle = 120°

Formula to find length of an arc ,

  $\longrightarrow \sf Length \ of \ an \ arc = 2\pi r \times \dfrac{x}{360}$

Here x = central angle

$\sf \Longrightarrow Length \ of \ the \ arc = 2 \times \pi \times 21 \times \dfrac{120}{360}$

                              $= \sf 2 \times \dfrac{22}{7}\times 21 \times \dfrac{1}{3}$

                              $= \sf 2 \times 22 \times 3 \times \dfrac{1}{3}$

                              $= \sf 2 \times 22$

                              $\sf = \bf 44 \ cm$

HOPE IT HELPS U.................. :)