return totalArea;
        }


        function countTriangleArea(a, b, c) {
            let area = 0;
            
            const side = [];//存储三条边的长度;
        
            side[0] = Math.sqrt(Math.pow(a[0] - b[0],2)+Math.pow(a[1] - b[1],2) + Math.pow(a[2] - b[2],2)); 
            side[1] = Math.sqrt(Math.pow(a[0] - c[0],2)+Math.pow(a[1] - c[1],2) + Math.pow(a[2] - c[2],2));
            side[2] = Math.sqrt(Math.pow(c[0] - b[0],2)+Math.pow(c[1] - b[1],2) + Math.pow(c[2] - b[2],2)); 
      