Circumference/ arc length

[sufinaz]

C=2x3.14xr

doesn’t work! Any help

 

[pka]

Look HERE.
$\large L=2\pi r\dfrac{\theta}{360}$

 

[HallsofIvy]

Since you are given the circumference of the circle rather than the radius it is simpler to use:
60 is 60/360= 1/6 of the entire circle so the arc length is 1/6 the circumference.
36 is 36/360= 1/10 of the entire circle so the arc length is 1/10 of the circumference.

 

[HallsofIvy]

C=2x3.14xr

doesn’t work! Any help

Your formula is the formula for the entire circumference (approximately- it's actually $\displaystyle C=2\times\pi \times r$ and $\displaystyle \pi$ is approximately 3.14). But the problem tells you that the circumference is 420 mm so there is no reason to use it.