Answer:
43 degrees
Step-by-step explanation:
DE is the diagonal of rectangle AEDH
CF is the diagonal of the opposite rectangle BFGC
Since opposite diagonals of a cuboid are equal, we therefore have that:
CF=DE=9.3cm
Also,
BC=6.8cm
In Triangle BFC, Angle B =90 degrees, therefore Triangle BFC is a right triangle.
We are required to determine the angle between CF and the plane ABCD.
This is Angle BCF in Right Triangle BFC.
Using Trigonometry
[tex]\cos \theta = \dfrac{6.8}{9.3}\\\theta=\arccos \dfrac{6.8}{9.3}\\\theta=43.0^\circ[/tex]
Therefore:
Angle BCF=43 degrees.
The angle between CF and the plane ABCD is 43 degrees.
