Hello from MrBillDoesMath!
Answer:
RT = sqrt(110)
Discussion:
The geometric situation shown arises when one is proving the Pythagorean theorem using similar triangles. A key result, because of triangle similarity, is that
QT/RT = RT/TS => cross multiply
RT^2 = QT * TS => substitute our numbers
RT^2 = 5 * 22
RT^2 = 110
RT = sqrt(110)
Thank you,
MrB