Bài 4: Sửa đề: F là hình chiếu của E trên CD

a: Xét ΔEAD vuông tại A và ΔEBC vuông tại B có

\(\hat{AED}=\hat{BEC}\) (hai góc đối đỉnh)

Do đó: ΔEAD~ΔEBC

=>\(\frac{EA}{EB}=\frac{ED}{EC}\)

=>\(\frac{EA}{ED}=\frac{EB}{EC}\)

Xét ΔEAB và ΔEDC có

\(\frac{EA}{ED}=\frac{EB}{EC}\)
\(\hat{AEB}=\hat{DEC}\) (hai góc đối đỉnh)

Do đó: ΔEAB~ΔEDC
b: Xét ΔCFE vuông tại F và ΔCAD vuông tại A có

\(\hat{FCE}\) chung

Do đó: ΔCFE~ΔCAD

=>\(\frac{CF}{CA}=\frac{CE}{CD}\)

=>\(\frac{CF}{CE}=\frac{CA}{CD}\)

Xét ΔCFA và ΔCED có

\(\frac{CF}{CE}=\frac{CA}{CD}\)

góc FCA chung

Do đó: ΔCFA~ΔCED

=>\(\hat{CAF}=\hat{CDE}\)

mà \(\hat{CDE}=\hat{CAB}\)

nên \(\hat{CAF}=\hat{CAB}\)

=>AC là phân giác của góc BAF

tuổi trẻ;)

report

\(\text{⩷!⨙┏⇴⨗⨜}\)

Tớ cảm ơn

Câu hỏi của Thd - Toán lớp 5 - Học trực tuyến OLM

bạn ấn vào link trên nhé

\(\dfrac{7}{8}-\dfrac{7}{16}-\dfrac{11}{32}=\dfrac{7.4}{8.4}-\dfrac{7.2}{16.2}-\dfrac{11}{32}=\dfrac{28}{32}-\dfrac{14}{32}-\dfrac{11}{32}=\dfrac{28-14-11}{32}=\dfrac{3}{32}\)

Uh, mik thông cảm với bn

Cố lên và mọi chuyện sẽ tốt hơn

thì bn xóa kb với người đó thôi -_-

xong bn tìm chỗ chức năng nt xong vô hiệu hóa là đc

1 A new hospital is being built by these workers now

2 A new power plant is being built by my mother

3 Chickens and ducks are being fed by Mary

4 A shirt is being made by me for Tom's birthday

5 This old bus station is being repaired

6 Book is being read by the teacher while pupils are doing the test

7 His homework is not being done by Nam now

8 Trees are not being planted by us at the moment

9 Is your car being repaired now

10 Are the flowers in the garden being cut by her?

III

1 Thirty house were destroyed by the storm

2 Some books were bought by him yesterday

3 Mary was called by him yesterday

4 That house wasn't sold last Sunday

5 A new hospital was built by these workers last years

6 This room isn't used a week ago

7 Mary was sent some money by her parents

Some money was sent to Mary by her parents

8 I was bought a new house by my mother

A new house was bought for me by my mother