I understand most of it (as there are solutions with it), but theres one part of the solutions I don't understand.
h^2 . (tan20)^2 = h^2 . (tan10)^2 + 1600 . (tan20)^2 . (tan10)^2
this then goes to:
h^2 = [ 1600 (tan20)^2 . (tan10)^2 ] / [ (tan20)^2 - (tan10)^2 ]
How does this happen? Subbing the final solution back in works aswell.
h^2 . (tan20)^2 = h^2 . (tan10)^2 + 1600 . (tan20)^2 . (tan10)^2
this then goes to:
h^2 = [ 1600 (tan20)^2 . (tan10)^2 ] / [ (tan20)^2 - (tan10)^2 ]
How does this happen? Subbing the final solution back in works aswell.