Answer:
L = 8.366
Step-by-step explanation:
Given
A(0,0,0)
H(3,5,6)
we can apply the equation
L = √((xH-xA)²+(yH-yA)²+(zH-zA)²)
where L is the length of the diagonal of the box
then
L = √((3-0)²+(5-0)²+(6-0)²)
⇒ L = √(9+25+36) = √70
⇒ L = 8.366
We can see the box in the pic shown.