Question

The length of AB is __

Answer 1

AB = 3.5π

Explanation:

The length of arc AB is calculated as

AB = circumference of circle × fraction of circle

= 2πr ×
`(90)/(360)` ( r is the radius and r = 7 )

= 2π × 7 ×
`(1)/(4)`

=
`(14\pi )/(4)` = 3.5π

Answer 2

The length of arc AB = 10.99 inch.

Explanation:

We know that,

The length of any arc of a circle = Radius of circle
`*` Angle subtended by arc at centre of circle.

According to the figure,

Angle subtended by arc at centre,
`\alpha` =
`(\pi )/(2)`

Radius of the circle,
`R` = 7 inch.

The length of arc AB =
`R*\alpha`

=
`7*(\pi )/(2)`

= 10.99 inch.