Given:
OP = 20 in
QP = 26 in
Since R is the midpoint of OP, then, OR = RP
Thus

To find the length of QR, use pythagoras theorem below:

Input values into the formula:

Subtract 10² from both sides:

Take the square root of both sides:
![\begin{gathered} \sqrt[]{QR^2}=\sqrt[]{26^2-10^2} \\ \\ QR=\sqrt[]{676-100} \\ \\ QR=\sqrt[]{576} \\ \\ QR=24 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/lw691cp2cddco8z0qft4mtvwd3difxfms9.png)
Therefore, the length of QR is 24 in