Calcular o perimetro do triangulo de vertices A(0,1,2), B(-1,0,-1)e C(2,-1,0).

A distância entre A e B será: Dab^2= (-1-0)^2 + (0-1)^2 + (-1-2)^2 =11 => Dab=(11)^1/2 (raiz quadrada de 11) Entre B e C será: Dbc^2= [2-(-1)]^2 + (-1-0)^2 + [0-(-1)]=11 => Dbc =(11)^1/2 Entre A e C será: Dac^2= (2-0)^2 + (-1-1)^2 + (0-2)^2=12 => Dac=2.(3)^1/2 (duas vezes a raiz quadrada de 3) Logo o perímetro 2p será igual a: (11)^1/2 + (11)^1/2 + 2.(3)^1/2 = 2.(11)^1/2 + 2.(3)^1/2=> 2p =2.[(3)^1/2 + (11)^1/2]