Question 305803
Just like in 2D,
{{{xm=(1/2)(x1+x2)=(1/2)(5-2)=3/2}}}
{{{ym=(1/2)(y1+y2)=(1/2)(6+5)=11/2}}}
{{{zm=(1/2)(z1+z2)=(1/2)(-3-7)=-5}}}
Distance formula
{{{D^2=(x1-x2)^2+(y1-y2)^2+(z1-z2)^2}}}
{{{D^2=(5-(-2))^2+(6-5)^2+(-3-(-7))^2}}}
{{{D^2=49+1+16}}}
{{{D^2=66}}}
{{{D=sqrt(66)}}}