Use the fact that the length of an arc intercepted by an angle is proportional to the radius to find the arc length given the circle area a = 16π cm2 and θ = π 3 .

The length of the arc is: L=4π/3 cm

Length of arc: L=?

L=r Θ

Central angle: Θ=π/3
Radius: r=?

Area of the circle: A=16π cm^2

A=π r^2

Replacing A=16π cm2 in the equation above:
16π cm^2=π r^2

Solving for r: Dividing both sides of the formula by π:
(16π cm^2)/π=(π r^2)/π

16 cm^2=r^2

Square root both sides of the formula:
sqrt( 16 cm^2)=sqrt(r^2)
4 cm=r
r=4 cm

L=r Θ
L=(4 cm)π/3
L=4π/3 cm

This is the graph x=1