Rectangular Prism Diagonals: Identifying Equal Interior Lines in 3D Geometry

Question

Look at the dotted diagonal in the figure below.

Which diagonals of the rectangular prism are equal?

00:00 How many identical diagonals are there to the drawn diagonal?

00:03 A face in a box is a rectangle

00:06 In a rectangle, the diagonals are equal to each other

00:12 In a box, opposite faces are equal

00:25 Equal rectangles have equal diagonals

00:36 And this is the solution to the question

Let's look at the face AEHD

In it, there is another diagonal equal to ED, which is AH

Let's look at the face BFGC which is identical and equal to AEHD, in which there are two diagonals that are also equal to ED:

$FC=BG=ED$

$AH,BG,FC$