The Triangle class contains:

$$ Three double data fields named side$1,$ side$2,$ and side$3$ with default values $1\mathrm{.}0$ to denote three sides of the triangle

$$ A no$-$arg constructor that creates a default triangle

$$ A constructor that creates a triangle with the specified side$1,$ side$2,$ and side$3$

$$ The accessor methods for all three data fields

$$ A method named getArea$()$ that returns the area of this triangle

$$ A method named getPerimeter$()$ that returns the perimeter of this triangle

$$ A method named toString$()$ that returns a string description for the triangle

$$ The toString$()$ method is implemented as follows:

return "Triangle: side$1="+$ side$1+"$ side$2="+$ side$2+"$ side$3="+$ side$3$;