Question 99712
you have to use the distance formula: {{{sqrt((x[2]-x[1])^2+(y[2]-y[1])^2)}}} on one of the sides.
if you put the points on graph paper it becomes obvious that 36 and 15 are the lengths of 2 of the sides. and the 3rd side is the hypotenuse.
now you can use the formula above or the pythagorean theorum: a^2+b^2=c^2
36^2+15^2=c^2
1296+225=1521
sqrt(1521)=39 (one way)
{{{sqrt((-12-24)^2+(8+7)^2)}}} 
{{{sqrt((-36)^2+(15)^2)}}} 
{{{sqrt(1296+225)}}} 
{{{sqrt(1521)=39}}} (another way)
Ed