Question

How long is the arc intersected by a central angle of π/2 radians in a circle with a radius of 4.5 cm? Round your answer to the nearest tenth. Use 3.14 for π

Answer 1

PI/2 equals 90 degrees
circumference = 3.14 * 2 * 4.5
Use the formula:
arc length = circumference • [central angle (degrees) ÷ 360]
arc length = 28.26 * (90 / 360)
arc length = 7.065 cm

Answer 2

7.1 cm

Explanation:

Since, the arc length formula in a circle formula is,

`l=r* \theta`

Where,

r is the radius,

`\theta` is the central angle ( in radians ) formed by the arc,

Here,

r = 4.5 cm,

`\theta=(\pi)/(2)`

Hence, the arc length would be,

`l=4.5* (\pi)/(2)`

`=(4.5* 3.14)/(2)`

`=(14.13)/(2)`

`=7.065\text{ cm}\approx 7.1\text{ cm}`