Question

Find the exact length of the midsegment of the trapezoid with the vertices S(−2, 4), T(−2,−4), U(3,−2), V(13, 10).

Answer 1

Check the picture below.

first off we'll need to know the midpoints of ST and UV, well, from ST as you can see in the picture, is just a vertical line, so its midpoint is simply (-2,0), let's find it for UV

$\bf ~~~~~~~~~~~~\textit{middle point of 2 points } \\\\ U(\stackrel{x_1}{3}~,~\stackrel{y_1}{-2})\qquad V(\stackrel{x_2}{13}~,~\stackrel{y_2}{10}) \qquad \left(\cfrac{ x_2 + x_1}{2}~~~ ,~~~ \cfrac{ y_2 + y_1}{2} \right) \\\\\\ \left(\cfrac{13+3}{2}~~,~~\cfrac{10-2}{2} \right)\implies \left( \cfrac{16}{2}~~,~~\cfrac{8}{2} \right)\implies (8~~,~~4) \\\\[-0.35em] ~\dotfill$

$\bf ~~~~~~~~~~~~\textit{distance between 2 points} \\\\ (\stackrel{x_1}{-2}~,~\stackrel{y_1}{0})\qquad (\stackrel{x_2}{8}~,~\stackrel{y_2}{4})\qquad \qquad d = \sqrt{( x_2- x_1)^2 + ( y_2- y_1)^2} \\\\\\ d = \sqrt{[8-(-2)]^2+[4-0]^2}\implies d=\sqrt{(8+2)^2+(4-0)^2} \\\\\\ d=\sqrt{10^2+4^2}\implies d=\sqrt{116}\implies d\approx 10.77$