having troubles creation an object for an abstract class in my main function c++ visual studio

Question

I have be getting the following error when compiling the code as as i create a new object for my class Animal.

    // here is the error i get whenh compiling the code as soon as i create the new object dog from class Animals

     /*
    1>template.obj : error LNK2019: unresolved external symbol "public:       __thiscall Animals::~Animals(void)" (??1Animals@@QAE@XZ) referenced in function _main
     1>template.obj : error LNK2019: unresolved external symbol "public: __thiscall Animals::Animals(void)" (??0Animals@@QAE@XZ) referenced in function _main
     1>C:\Users\Mein PC\Desktop\AltranProject\Debug\AltranProject.exe : fatal error LNK1120: 2 unresolved externals
    */ 

The class ActiveParticipants is my abstract class (in header folder) and the class Animals (in header older) inherit from ActiveParticipant. but as soon as i create a new object from my main function (Template.cpp from source Files) to set some paraders i get a compiling error. any help in solving the problem would be appreciated.

   #pragma once
   #include <string>
   using namespace std;

      class ActiveParticipants
   {
        public:
        ActiveParticipants(void);
      // pure virtual functions for the interface framework


       virtual int defineParticipant() = 0;

      void setVolume(int v)
       {
         volume = v;
       }

       void setWeight(int w)
        {
           weight = w;
        }

        void setHeight(int h)
          {
              height = h;
          }

       void setLegs(int l)
        {
          legs = l;
        }

      void setLength(int Nlength)
       {
          length = Nlength;
       }

       void setWheels(int Nwheels)
         {
           wheels = Nwheels;
         }

       protected:
         int volume;
         int weight;
         int height;
         int length;
         int wheels;
         int legs; 

      ~ActiveParticipants(void);
   };






     // here is a sample class Animals inheriting from the abstract             class ActiveParticipants

    #include "ActiveParticipants.h"

     #pragma once
    class Animals: public ActiveParticipants
     {
       public:
       Animals(void);
       int getParticipant()
       {

          return (legs, height, weight);
      }
         ~Animals(void);
    };



      // here is my main function 

        #include "Animals.h"
        #include "ActiveParticipants.h"

      int main(int argc, char* argv[])
     {
         Animals dog; // needs to create an object of type Animals
         // and sets its parameters over here 
            dog.setHeight(1);
            dog.setLegs(4);
            dog.setWeight(10);
        // then print those given parameters out here
     std::cout<<"Here are the parameters for the Dog:\n" <<dog.getParticipant()<<std::endl;

          system("pause");

          return 0;
       }