Chủ đề định lý Thales - Bài tập 5.

Hello everyone, today I'm going to share with you a new calculation with the theme of detailed. The calculation is very simple. For the x-axis, I give the form ABCD. There is Mn parallel to AB, N belongs to AD, N belongs to BC. And there is Am by 3, Md by 6, Bn is x, Nc is 8. Now we need to calculate the magnitude of Bn. There is Mn parallel to AB, and parallel to DC. As we know, to find x, we need to set a value or a value less than x. In this lesson, I will set a value less than x. If you have watched the previous video, you can guess the value less than x. You can guess Am by Md is equal to Bn by Nc. Am by Md is equal to Bn by Nc. Now we need to prove that this formula is correct. The way to prove is the same as in the previous video. I will connect A and C and prove using the initial value. I will prove this formula. When the proof is complete, I just need to replace the numbers. Am by Md is equal to 3 by 6, Bn is x, Nc is 8. x is equal to 3 by 8 divided by 6 is equal to 4. When x is equal to 4, Bn is equal to 4. This formula is quite simple. Let's move to the second lesson. This is x, not Bn. The formula is as follows. Am by Md is equal to Bn by Nc. Mn is x, Bn is 6, Nc is 14. Now I need to find x. This formula is more complicated than the first one. So how do I solve this formula? To calculate the length of a straight line. I have an example like this. I have a piece of land. I need to calculate the area of this piece of land. The mathematician will divide this piece of land into triangles. Then he will calculate the area of these triangles. Then he will add up the area of this big triangle. The result is the same. Now we want to calculate the length of a straight line. We divide this straight line into smaller triangles. Then we calculate the length of smaller triangles. Then we add them up. The result is the number of big triangles. How do we divide the length of a straight line? The mathematician will connect A, C and cut off Mn. That is the point where we divide Mn. x, connect A, C. connect A, C. cut off Mn into P. Then Mn is equal to Mp plus Pn. To calculate Mn, we calculate Mp and Pn. To calculate Mp, it is quite simple. When we apply the effect of the Taylor equation in the triangle ADC, there is Mp equal to DC. And the same with Pn. Now let's go to the mathematics lesson. The lesson is as follows. Connect A, C. and connect A, C. and cut off Mn into P. We get Mp is equal to DC. And Np is equal to AB. Because Mn is equal to AB, equal to CD. Now let's calculate Mp. ADC has Mp is equal to CD. Mp is equal to AM over AD is equal to MP over DC. According to the Taylor equation. We get Mp is equal to AM over AD is equal to 3.6. AD is equal to 6.3 is equal to 9. 3.9 is equal to MP over DC. DC is equal to 14. MP is equal to 3.14 divided by 9. 3.14 divided by 9 is equal to MP. Next, let's calculate CAB. CAB has Np is equal to AB. Np over AB is equal to AB is equal to CN over CB is equal to CP over CA. According to the equation. We need to change the number to get Pn. But we don't know Cn over Cb. We don't know Cp over Ca. So we need to calculate Cn over Cb or Cp over Ca. Let's calculate Cp over Ca. Cp over Ca is equal to DM over DA. Cp over Ca is equal to ADC. Here is the equation. ADC has Mp is equal to DC. ADC has MD over DA is equal to CN over Cb or Cp over Ca. Let's change the number to get Cp over Ca. MD over DA is equal to 6 over 9. Cp over Ca is equal to 2 over 3. Let's change the number to get Cp over Ca. Cp over Ca is equal to 2 over 3. Let's change the number to get Cp over Ca. Cp over Ca is equal to 2 over 3. We have calculated Np and Mp. We have x is equal to Mp plus Np. Mp plus Np is equal to 3 times 14 over 9. Mp plus Np is equal to 3 times 14 over 7. Mp plus Np is equal to 3 times 4 over 4. Mp plus 4 is equal to 2 times 6 over 3. The result is x is equal to 2 times 6 over 3. That's all for this lesson. In this lesson, we will strengthen the theory of talent and the effect in chess. In order to calculate the length of a piece of chess, we can divide it into smaller pieces. We will divide it into smaller pieces and calculate each piece. Then we will add them together. This will give us the power to connect the diagonal lines AC in the table. In the table, there is a river. We can connect AC or BD. Then we will continue to think. See you in the next video.