For I1
excenter [ 1 ] [ 0 ] = ( ( - ( a * x1 ) + ( b * x2 ) + ( c * x3 ) ) // ( - a + b + c ) ) NEW_LINE excenter [ 1 ] [ 1 ] = ( ( - ( a * y1 ) + ( b * y2 ) + ( c * y3 ) ) // ( - a + b + c ) ) NEW_LINE