hsider the following class declarations.

public class point

i

private double $x\frac{\text{;}}{\frac{?}{?}}x-$coordinate

private double $y$; $//y-$coordinate

public $($point $()$

$\{$

$x=0$;

$y=0$;

$3$

public point$($double $a,$ double b$)$

$\{$

$x=a$;

$\}$

$y=b$;

$1/$ There may be instance variables. constructors, and methods that are not shown. $\}$

public class circle

i

private point center:

private double radius:

$l^{****}$ Constructs a circle where $(a,b)$ is the center and I is the radius. $**1$

public circle $($double $a,$ double $b,$ double $r)$

$\{$

$\frac{?}{?}*$ missing code $*/$

$3$