Answer:
A; 8.60
Step-by-step explanation:
[tex]a^{2} +b^{2} = c^{2}[/tex]
[tex]7^{2} + 5^{2} = c^{2}[/tex]
[tex]49+25=c^{2}[/tex]
[tex]74=c^{2}[/tex]
[tex]\sqrt{74} =c[/tex]
8.60 = c
8.40 cm
7^2+5^2=x^2
49+25=x^2
74=x^2
x≈8.6