Help me and pls explain how you got the answer

Answer:
The length of the missing side is 8.5 ft
Step-by-step explanation:
To find the length of the missing side, we can use the Pythagorean theorem which states [tex]a^2 + b^2 = c^2[/tex] where c is the length of the longest side of a right-angle triangle while a and b are the other two sides. Note that the Pythagorean theorem ONLY applies to right-angle triangles.
[tex]a^2+b^2=c^2\\(6)^2+(6)^2=36+36=72=c^2\\\\c=\sqrt{72}= 8.48[/tex]
Rounding to the first decimal place, we get c = 8.5ft