# Help Needed finding length, midpoints, given endpoints

#### Rafael De La Ghetto

##### New member
How do you do this?

1) Find the length of the following segment created by these pairs of endpoints: (3, 6), (2, 1)

2) Find the midpoint of the following segment created by these pairs of endpoints: (2, -6), (5, 8)

Thanks for any replies.

#### pka

##### Elite Member
You should have these in your text material.
$$\displaystyle \L \begin{array}{l} P:\left( {a,b} \right)\quad \& \quad Q:\left( {s,t} \right)\quad \Rightarrow \quad d(PQ) = \sqrt {\left( {a - s} \right)^2 + \left( {b - t} \right)^2 } \\ \left( {\frac{{a + s}}{2},\frac{{b + t}}{2}} \right) \\ \end{array}$$

d(P,Q) is the length of line segment PQ.
The mid-point is the second expression.