Вычислить периметр треугольника abc, если a(4,0),b(7,4),c(-4,6)

 A(4,0),B(7,4),C(-4,6)
AB={7-4;4-0}                           BC={-4-7;6-4}                                  AC={-4-4;6-0}
AB={3;4}                                 BC={-11;2}                                      AC={-8;6}
|AB|=√3²+4²=√9+16=              |BC|=√(-11)²+2²=√121+4=               |AC|=√(-8)²+6²=
 √25=5                                      =√125=5√5                                   =√64+36=√100=10

P=|AB|+|BC|+|AC|=5+5√5+10=15+5√5