Question

in the figure below, s is between q and t, and r is the mid - point of $overline{qs}$. if $rs = 7$ and $qt = 20$, find $st$.

Explanation:

Step1: Find length of QS

Since R is the mid - point of $\overline{QS}$ and $RS = 7$, then $QS=2\times RS$. So $QS = 2\times7=14$.

Step2: Find length of ST

We know that $QT=QS + ST$. Given $QT = 20$ and $QS = 14$, we can solve for $ST$. Rearranging the formula gives $ST=QT - QS$. So $ST=20 - 14 = 6$.

Answer:

6