If a leaning tree must be measured obtain the angle of lean from the vertical (use a plumb bob from the top of the tree and estimate the point on the ground where it would fall), measure the vertical height from the tree-top to the ground, and multiple this height by the secant of the angle of lean (see p. 38 of Husch, et al.).
(it; would fall; L:the ground) (a leaning tree; must be measured; obtain the angle of lean from the vertical) (a leaning tree; obtain; the angle of lean from the vertical)
it a leaning tree a leaning tree
would fall must be measured obtain
L:the ground
obtain the angle of lean from the vertical
the angle of lean from the vertical