A plane mirror made of a very thin piece of glass lies flat on the ground. As shown in the following figure, one end of the mirror is 2.1 m from you and the other end is 40 m from a nearby tree. You are1.4 m tall, and the mirror has a length L. The mirror is arranged so that you can now see the image of the top of the tree at one edge of the mirror.
1) How tall is the tree?
2) If you can now see a point halfway up the tree at the other edge of the mirror, what is L?