1)Cho tám giác ABCD,gọi E,F,G,H theo thứ tự là trung điểm của AB,BC,CD,DA

a)Chứng minh: tứ giác EFGH lầ hình bình hành

b)Tìm điều kiện của tứ giác ABCD để EFGH để EFGH lầ hình

b1)Hình chữ nhật

b2)Hình thoi

b3)Hình vuông

Cho tam giác abc vuông tại A (AB<AC) đường cao AH,từ H vẽ HE,HF lần lượt vuông góc với AB,AC (E thuộc AB) (F thuộc AC)                                                                                                 a) Chứng minh AH=EF                                                                                                                b) Trên tia FC xác định điểm K sao cho FK=AF

I.Underline and correct the mistakes  in the following sentences

1.Lan Anh enjoys to watch caartoons on TV

2.How many student are there in Long's class?

3.She alway tries to complete her homework before to watch her favorite show on TV

4.Tuan is lucky for enjoy British festival

5.For some people,washing clothes are hard work

6.There is beautiful clock on the wall

7.While we were young,we used to have a change to visit Brazil

8.Hoa Ban festival alway full at songs and prayers

9.The 54 ethnic people at Vietname live peaceful

10.There alway regional differences in every countries

I.Underline and correct the mistakes  in the following sentences

1.Lan Anh enjoys to watch caartoons on TV

2.How many student are there in Long's class?

3.She alway tries to complete her homework before to watch her favorite show on TV

4.Tuan is lucky for enjoy British festival

5.For some people,washing clothes are hard work

6.There is beautiful clock on the wall

7.While we were young,we used to have a change to visit Brazil

8.Hoa Ban festival alway full at songs and prayers

9.The 54 ethnic people at Vietname live peaceful

10.There alway regional differences in every countries