Rectangle

$-$length:float $=1\mathrm{.}0f$

$-$width:float $=1\mathrm{.}0f$

$+$Rectangle$()$

$+$Rectangle$($length: float, width: float$)$

getLength$()$:float

$+$setlength$($length: float$)$: void

$+$getWidth$()$:float

$+$setWidth$($width: float$)$: void

$+$getArea$()$:double

$+$getPerimeter$()$:double

toString$()$: String