Question 915957
D = {{{sqrt ((x[1]-x[2])^2+(y[1]-y[2])^2))}}}
A (20,20), 
B (-12,-4) AB =  {{{sqrt(32^2 + 24^2)}}} = 40
C (4,-12)? BC = {{{sqrt(-16^2 + 8^2) = sqrt(320)}}} 8√5
A (20,20), AC = {{{sqrt(-32^2 + -16^2) = sqrt(1280)}}} = 16 √5
P = 40 + 24√5