Thread: Fly in a Box

A fly is inside an empty, closed, rectangular box that measures two feet by three feet by six feet. If he flies from one corner to the opposite corner, what is the minimum distance he must travel?

How do I solve this?

Thanks

Use Pythagorean Theorem twice.

Use once to get one length (a) of the blue triangle.

Use another time to get the hypotenuse (c) of the blue triangle.