Respuesta :

Answer:


Step-by-step explanation:

RT = sqrt(20^2 - 16^2)

RT = sqrt(400 - 256)

RT = sqrt(144)

RT = 12


SR/ST=  QR/QT

SR/12 = 20/16

SR = 12 x 20 / 16

SR = 240/16

SR = 15


answer is C.

15 Units