(a(i))[1]
State the size of angle $x$.
(a(ii))[1]
Give the mathematical name of this kind of angle.
(b)[3]
Determine the value of $y$.
(c(i))[1]
Identify the mathematical name of line FG.
(c(ii))[1]
Explain the reason that $\angle EFG$ is $90^\circ$.
(c(iii))[2]
Calculate the circle's area.