Answer:
H. 13
Explanation:
Make use of the Pythagorean theorem twice. The first time, use it to find TS. The second time, use it to find QR.
TS² + RT² = RS²
TS² = RS² -RT² = 64 -48 = 16 . . . . subtract RT², fill in numbers
TS = 4 . . . . . take the square root
Now, QT = QS -TS = 15 -4 = 11, so ...
QR² = QT² +RT²
QR² = 11² +(4√3)² = 121 +48 = 169
QR = √169 = 13
The length of QR is 13.