Áp dụng định lý thales trong tam giác có :

DE\\AC nên AE \ AB=CD \ BC

DF\\AC nên AF \ AC = BD \ BC

Khi đó : AE \ AB + AF \ AC = CD \ BC + BD \ BC = BC \ BC = 1

Today , i would like to talk about Tet holiday . Tet is one of the most important festival in Viet nam. Tet occurs from one day to third day of the firts lunar month , Before Tet , my family cleans the house and decorates it with flower. We also buy new clothes and cook traditonal food like Chung cake . On the firts day of Tet , we visit our grandparent and gives New Year wishes . Children receive lucky money in red envelopes. I love Tet, because it is a happy time for family!

1 The Muong earn a living by farming and raising anmals

2 They are in the habit of exercising after work

1 If you don't drink more water , you will get more ance

2 My sister want to see the terraced fields, so she going to Sapa

3 Unless he spends time on his phone, he will complete his work

Teenagers today face many challergers in their daily lives. One of the most common problems is stress too much schoolwork. Many students feel under pressure because they want to get good grades and make their parents pround. Another pronlem is peer pressure and bullying . Teenagers sometimes try to behave like their frends even when they don't really want to . This can lead to unhealthy habits , such as spending too much time on social media or not focusing on their studies.