Jawabanmu

2014-08-03T13:26:33+07:00
Menggunakan luas segitiga
1/2.PR.QS = 1/2.QR.TP
1/2.15.16 = 1/2.20.TP
15.8 = 10.TP
120 = 10.TP
TP = 120/10
TP = 12 cm

Menggunakan Phytagoras
PR^2 = TP^2 + RT^2
15^2 = 12^2 + RT^2
225 = 144 + RT^2
81 = RT^2
RT = 9 cm

Maka QT = 20-9 = 11 cm (B)