Chapter 12.4B, Problem 16A

To find the height of a tree, a group of Girl Scouts devised the following method. A girl walks toward the tree along its shadow until the shadow of the top of her head coincides with the shadow of the top of the tree. If the girl is $150\text{ cm}$ tall, her distance to the foot of the tree is $15\text{ m}$, and the length of her shadow is $3\text{ m}$, how tall is the tree?