Question

A small hole is made up of a window shutter of a room,10.5m wide and image of a tree outside the room cast on the opposite. If the image is 4.5m high and the tree is 30.5cm from the window, what is the height of the tree?

Answer 1

As we see, the triangles are similar:

$$\frac{30.5\cdot10^{-2}}{10.5}=\frac{H_T}{4.5},\\\space\\ H_T=0.131\text{ m}.$$

The tree is 13.1 cm high.