IMO E,C
for qstn1) neither of the statements are sifficient. and combining both, you can draw any number of circles with that ratio.
for qstn2: draw a chord parallel to the side containing two angles s.
the triangle formed is an equilateral triangle. Just by symmetry you can tell that the circumference will be 27
Using Statement 2, You can determine that it is a 60-60-60 Triangle...Therefore the arc XZ is 120 degrees, or 1/3 of the circle...Using Statement 1, you are told that the remaining portion of the circle, the other 2/3 is = to 18...