A way to measure the height of a tree is to measure the length of the tree's shadow and the length of the shadow of an object of some known height such as a yardstick.
(A way to measure the height of a tree; is; to measure the length of the tree's shadow and the length of the shadow of an object of some known height such as a yardstick)
A way to measure the height of a tree
is
to measure the length of the tree's shadow and the length of the shadow of an object of some known height such as a yardstick