I have the question "Calculate the angle between the line BH and the plane ABCD in the cuboid pictured below, giving your answer to 1 decimal place."
I have used the cosine rule for this question.
Here is my working:
So I created a triangle DBH and then found the sides BD and BH using Pythagoras.
I then put these values into the cosine rule and got the final answer of 84.6 degrees.
However the solutions say that the answer should be 34.5 degrees.
Have I used the wrong method ? Should I have used the sine rule ? I have not used the sine rule as there are no angles given.