Do the area of the circle as a whole minus (72/360 x radius^2) and then minus the other grey area.
Proportional reasoning is a form of mathematical reasoning that involves a sense of co-variation and of multiple comparisons, and the ability to mentally store and process several pieces of information. I hope my answer has come to your help. God bless and have a nice day ahead!
3/4 and 6/8 are equal and this is right I believe
