is it a good way to declare const cococs2d::CCRect in a shared constant.h header file?

cocos2d-x C++
#1

Code in the project-shared constant.h file
@
#include “cocos2d.h”
USING_NS_CC;

CCRect RECT_TOUCH_AREA = CCRectMake(0, 0, 720, 140);
@
Then in all .cpp files included this constant.h file prompts error:
multiple definition of `RECT_TOUCH_AREA’

But other int, float, string, enum valued defined in the constant.h are running well.

#2

if you wanna make a global variable you’d better write like this.
//xx.h
extern int a;

//xx.cpp
int a = 10;