Please help me to answer this question because I don’t understand how to answer it

Question

The get Area function returns a double number and has no formal parameters .

A) Rewrite a valid function call getArea and assign its return value to a double variable named area.

B) Rewrite a valid function prototype for the getArea function from question a.

Answer 1

double area = getArea();

//no arguments passed to function, returns double value so stored in a double variable.

Prototype :
double getArea(void) ;
Prototype is consist return type, function name, function parameter types sequentially as in implementation.. Should included before using it (at begin).