People decorate evergreen trees for Christmas, because they stay green all year, even in the wintertime. However, the trees do not keep their needles forever. Once a needle has been growing on a Ponderosa Pine Tree for three to five years it will turn brown and fall off, so another new needle can grow in its place. The newer needles remain green during this process, so it is not noticeable.
Make your own tree and learn about symmetry.
Start by drawing half a tree on an index card, and cutting it out. Think of the straight edge on the index card as the middle of the tree. Next, place two pieces of constructing paper together and fold them over. Line the straight edge of the index card up with the folded edge of the papers and trace your half of a tree.
Cut along the line you drew, and then unfold the paper. Now you have two symmetrical tree! The sides are mirror images of each other.
Repeat the process, so you have six trees in total. Carefully line up the trees and staple them together along the line of symmetry.
Now you can fold fan the pieces of paper out, creating a three dimensional tree.