Respuesta :
Step-by-step explanation:
if these are the lenghs you meant the we use this formula
[tex] {a}^{2} + {b}^{2} = {c}^{2} [/tex]
12^2+8^2=c^2
144+64=208
[tex] {c}^{2} = 208[/tex]
c=14.22

Answer:
17
Step-by-step explanation:
(RS)2 + (ST)2 = (RT)2
(9 in)2 + (12 in)2 = (RT)2
81 in2 + 144 in2 = (RT)2
225 in2 = (RT)2
15 in = RT