Question

Can anyone teach mee..................... ​

Answer 1

(i) The name of the part of the circle, OQ is a radius

(ii) The radius of the sector QOR is 21 cm

Explanation:

The given figure is a sector of the circle O

∵ Any sector of a circle formed from 2 radii and an arc

∴ OQ is a radius

(i) The name of the part of the circle, OQ is a radius

The rule of the length of an arc of a circle is L =
`(\alpha )/(360)` × 2 π r, where

• α is the angle of the sector

• r is the radius of the circle

∵ The length of the arc QR is 22 cm

∴ L = 22

∵ The measure of the angle of the arc is 60°

∴ α = 60°

∵ π =
`(22)/(7)`

→ Substitute them in the rule above

∵ 22 =
`(60)/(360)` × 2 ×
`(22)/(7)` × r

∴ 22 =
`(22)/(21)` r

→ Divide both sides by
`(22)/(21)`

∴ 21 = r

(ii) The radius of the sector QOR is 21 cm