Answer:
the unknown side of the triangle is [tex]2\sqrt{21}[/tex]
Step-by-step explanation:
[tex]a^2+b^2=c^2[/tex]
[tex]4^2+b^2=10^2[/tex]
[tex]16+b^2=100[/tex]
[tex]b^2=100-16[/tex]
[tex]b^2=84[/tex]
[tex]b=\sqrt{84}[/tex] or [tex]2\sqrt{21}[/tex]
