I think that is the answer because it says 2/5 where two rows are shaded and three more rows remain unshaded so, when you add that three and two it's altogether 5, so I think that is the answer, please check out the document I have uploaded.
Answer:
6.47
Since it's just asking for the other side of the diameter, it's equivalent to the radius given already.
563*(10*10*10) that's you scientific notation
By Pythagoras Theorem,
the length of the other leg= (63^2-52^2)^1/2
hope this helps :)