Shape functions : These functions serve to introduce the concept of polymorphism and object$-$oriented programming. You will be programming two types of objects that represent shapes. The rectangle$\_$t type represents a rectangle shape with a width and length. The triangle$\_$t type represents an equilateral triangle with a length. Both types are based on a base shape$\_$t type that corresponds to the base class in an object$-$oriented language.

oriented programming. You will be programming two types of objects that represent shapes. The rectangle$\_$t type represents a rectangle shape with a width and length. The triangle$\_$t type represents an equilateral triangle with a length. Both types are based on a base shape$\_$t type that corresponds to the base class in an object$-$oriented language.Shape functions: an object$-$oriented language.double rectangle$\_$area$($void$*$ shap