The compiler makes the following remark about your code:
In function 'int width(double)':
84:1: warning: no return statement in function returning non-void [-Wreturn-type]
In function 'int height(double)':
114:1: warning: no return statement in function returning non-void [-Wreturn-type]
In function 'int area(double)':
151:1: warning: no return statement in function returning non-void [-Wreturn-type]