tolong yaa kak.............

PT = √(PR² - RT²)
PT = √(144 - 36)
PT = 6√3 cm

TQ = √(PQ² - PT²)
TQ = √(400 - 108)
TQ = 2√73 cm

RS/PT = RQ/PQ
RS/6√3 = (TQ - RT)/20
RS = 6√3 (2√73 - 6)/20
RS = 5,76 cm
RS = 5,8 cm (pembulatan)