Answer:
9 cm
Step-by-step explanation:
set up a proportion SR/NM=ST/NP, since you know all but one of the lines, sub them into the equation, 15/5=ST/3. solve the side you know to get 3=ST/3, multiply both side by 3 to eliminate the fraction and get the answer, 9=ST.
if you have any questions, leave them in the comments and i will try to answer them, if this helped, pls give brainliest
