a) Chứng minh \(\Delta\)ADB = \(\Delta\)ADC

\(\Rightarrow\) DAB = DAC

Do đó: DAB = 20^o : 2 = 10^o

b)\(\Delta\)ABC cân tại A, mà A = 20^o (gt)nên \(\Delta\)ABC = (180^o - 20^o) : 2 = 80^o

\(\Delta\)ABC đều nên DBC = 60^o

Tia BD nằm giữa hai tia BA và BC \(\Rightarrow\) \(\Delta\)ABD = 80^o - 60^o = 20^o. Tia BM là phân giác của góc ABD nên \(\Delta\)ABM = 10^o

Xét tam giác ABM và BAD có:

AB cạnh chung: \(\Delta\) BAM = \(\Delta\)ABD = 20^o

\(\Delta\)ABM = \(\Delta\) DAB = 10^o

Vậy: \(\Delta\)ABM = \(\Delta\)BAD (g.c.g) suy ra AM = BD, mà BD = BC (gt) nên AM = BC

I, Complete the following passage, then answer the questions

Mr. Lam is a farmer. He has some paddy fields anh he produces a lot of the rice. He has a few fruit trees, some animala and a garden of vegetable.

Questions:

1 What does Mr. Lam do?

Mr Lam is a farmer.​

2 How much rice does Mr. Lam produce?

He produces a lot of rice.

3 Does he have any paddy fields?

Yes, he does.

4 Does he have any vegetable gardens?

Yes, he does.