Answer:
The acute angle at which the diagonals intersect is:

Explanation:
An acute angle is an angle that measures less than 90 degrees.
Observe the rectangle attached, where
is the acute angle at which the diagonals intersect.
First, you need to find the measure of the angle β.
In order to find β, use this inverse trigonometric function:

In this case:

Then:
The angle
is twice the angle
. Then, this is:
