“图形”类shApE中定义了纯虚函数CAlArEA()，“三角形”类triAnglE继承了类shApE，请将triAnglE类中的CAlArEA函数补充完整。
&nBsp;ClAss shApE{ puBliC:&nBsp; virtuAl int CAlArEA()=0; }&nBsp;
ClAss triAnglE: puBliC shApE{
puBliC:&nBsp; triAnglE{int s, int h}: siDE(s),hEight(h) {}&nBsp;
【 】 { rEturn siDE*hEight/2&nBsp; }
privAtE:&nBsp;&nBsp;&nBsp;&nBsp; int siDE;&nBsp;&nBsp;&nBsp;&nBsp; int hEight; };