### Triangle

In this chapter we will discus about some properties of triangles. For basic definition, we let the reader to arrange as good as reader can do. We let the reader to find theirself knowledge and after that, they can arrange the definition of a triangle theirself.
To understanding the principal of a triangle, please do the project below.

Project #1:
It is given three segment lines. Their lengths are 10 cm, 7 cm, and 8 cm. Draw a triangle with three segments given.

Project #2:
Given segments line 5, 7, and 10 cm, label it with p, q, r.
1. Choose one segment given, construct an equilateral triangle, whose sides have the same length as that segment.
2. Construct a triangle such that one of the sides has the same length as p, while the two other sides have the same length as q.
3. Construct a triangle whose sides have lengths 5 cm, 7 cm, and 15 cm.
4. Can you explain why there is trouble with Problem 5?
5. >Draw any triangle just using a ruler, and measure the length of the three sides. Add up the lengths of any two sides and compare this total with the length of the third side. What do you notice?
6. Construct a triangle with sides of length 5 cm, 10 cm, and 15 cm. What happens?
7. Let P, Q, and M be three points in the plane, and suppose d(P, Q) + d(Q, M) = d(P, M). What can you conclude about point P, Q, and M? Draw a picture.
Now, can you tell me what a triangle is?