I need help on this please

Answer:
7.5
Step-by-step explanation:
because a^2+b^2=c^2 then:
a=5
c=9
b=?
so you do 9^2 - 5^2 which will give you 56, you square root 56 and get 7.48 which you round to 7.5 since it wants it in tenths
pls brainliest if you found it useful