The arc degree is equal to double that of the angle shown in the image.
Arc degree = 41 x 2 = 82
We know that a full circle is equal to 360 degrees. So, we can find the percentage that 82 is of 360.
82 / 360 = x / 100
360x = 8200
x = 22.8
22.8%
Hope this helps!! :)