I am trying to find out the height of the wall for my poly-tunnel construction.
Can you please let me know what the height of the the wall will be?
Update
Maybe the image below is the correct one. I want a lean-to roof with 15 degrees.
Update
I made some more research and I think the below image is what i want.
Let's make $DE \perp AE$. Then:
$$\tan 75°=\frac{DE}{AE}=\frac{10}{AE}=\tan(45°+30º)=\frac{\tan45°+\tan 30°}{1-\tan45°\cdot\tan 30°}$$
Now you can find $AE$ and then:
$$CD=BE=4-AE$$
Can you finish?