A quarter of a circle is 2/8 of a circle. Add to that an eighth (1/8) of a circle (not eight) and this equals 3/8 of a circle. This equates to 37.5 % of a circle.
since eight divided by 100 is 12 remander four it changes as a fravtion to 12 4dash 8 so twelve times two is twenty four and four eights times two is one 24 plus 1 equals twenty five doo its twenty...