Question

in the figure below, s is between q and t, and r is the midpoint of $overline{qs}$. if $rs = 2$ and $qt = 8$, find $st$.

Explanation:

Step1: Find length of QS

Since R is the mid - point of $\overline{QS}$ and $RS = 2$, then $QS=2\times RS$.
$QS = 2\times2=4$

Step2: Find length of ST

We know that $QT=QS + ST$. So, $ST=QT - QS$.
Given $QT = 8$ and $QS = 4$, then $ST=8 - 4$.
$ST = 4$

Answer:

$4$