A. You need to know the circumference formula:
[tex]C=2\pi r[/tex]
Replace r (4in):
[tex]C=2\pi(4in)=25.1in[/tex]
B. You need to know the arc of a circle formula:
[tex]s=\theta r[/tex]
The angle is in radians so convert 60° to radians
Remember that 180° are pi radians so:
[tex]60°*\frac{\pi}{180°}=\frac{1}{3}\pi rad[/tex]
Replace the angle in radians and the radius (4in)
[tex]s=\frac{1}{3}\pi *4in=4.2\text{ in}[/tex]
