Answer:
6.7cm
Step-by-step explanation:
We apply Pythagoras Theorem twice.
First we find out the diagonal of the base of the cuboid.
The diagonal of the base = sqrt (2^2+4^2) = sqrt (20).
Then we find out AB by applying Pythagoras Theorem.
AB^2 = 5^2 + [sqrt (20)]^2
AB^2 = 45
AB = 6.7cm (correct to 1 decimal place)
