I just play all day. Do you know how to read? "May Day Golden Week. Just as I was having fun, I suddenly heard the voice of a beautiful woman. If I didn't read it, I would know that my mother taught me again. [Mom, I have finished my homework. " I pouted and answered. [Then I will test you. If you do it right, I will reward you for playing for one day. "hey ..

Mother gave a question: [There is an isosceles triangle. The lengths of the two sides are 9 cm and 4 cm respectively. Do the calculations. What is the circumference of this triangle? "It's too simple, I can't listen to it. I really don't want to do it. But the thought of playing for a day makes me want to do it. I know that the focus of this problem lies in the diversity of conclusions. Well, my math teacher has said it many times. This is called the new curriculum.

So I began to analyze: [If the 9 cm side is regarded as the waist, the circumference of this triangle is 9 * 2+4 = 22 cm. If the 4 cm side is regarded as the waist, then the circumference of this triangle is 4 * 2+9 = 17 cm. ] Three times five divided by two. I proudly told my mother my thinking process. My mother smiled and said, [Go and show me the two triangles you just considered. "

What's wrong with building a triangle as long as I'm not allowed to study? Just build it. I'm happy to make a triangle. The first triangle was built soon. I did the same thing. Strangely, I enclosed it, but I couldn't spell out a triangle with a side length of 4 cm and a bottom of 9 cm. What happened? It seems that the second calculation method I analyzed earlier does not exist in life. Two sticks 4 cm long and one stick 9 cm long cannot be combined into a triangle. I put my head on my head and told my mother the result. My mother smiled and said, "You must pay attention to what you have learned. You must learn to be responsible for your own results. You can't take it for granted. "

My mother dropped this sentence and went to do housework. I'm not convinced. Did my mother give me special conditions? Isn't this possible under other circumstances? So, I continued my experiment. It turns out that 4 cm and 4 cm add up to only 8 cm, not 9 cm long. Of course, I can't spell it. At least it must be the same length. So I changed the other one to 5 cm. Still not working. I changed it to 5.5 centimeters. What about 5.4? I shortened it on purpose. It doesn't matter. I seem to understand something. Two short sticks add up to more than 9 cm. Is it true?/You don't say. So I opened the math book again. I measured three sides of many triangles. I found that both sides add up to be bigger than the other side. I still don't believe it. I drew more than 10 arbitrary triangles. After measurement and addition, the result is still the same. I believe that the sum of the two sides of a triangle is greater than the right side. I'm starting to get a little excited. I loudly said to my mother: [Mom, you are misleading me ..] My mother praised my scientific method of learning mathematics in time.

I went to school after May Day. I told this story to my classmates at the class meeting. After I finished, I proudly asked everyone if there were any questions. I didn't expect the monitor to ask loudly: [Your discovery is amazing. But we want to know why. "