Question

A triangle has points R(-2,0) ,S(2,8) and T (8,2) as shown in the group. M is the midpoint of RT . What is the length of SM

Answer 1

The midpoint is calculated by averaging the coordinates of its endpoints:

$M = \left(\dfrac{-2+8}{2},\dfrac{0+2}{2}\right)=(3,1)$

Now we can use the usual distance formula to get the length of SM:

$SM=\sqrt{(2-3)^2+(8-1)^2}=\sqrt{1+49}=\sqrt{50}$