How to calculate angle BCE?

Answer:
75.3 degrees ( to nearest tenth).
Step-by-step explanation:
If we take a section through the plane BCHE we get a rectangle.
BC = 2 cm and BE = √(7^2 + 3^2). ( By the pythagoras theorem).
tan < BCE = √(7^2 + 3^2) / 2.
So the m < BCE = 75.3 degrees.