181,558 views
20 votes
20 votes
Bài 2: Cho ∆ABC có AB AC = , M là trung điểm của BC . Trên tia đối của tia MA lấy điểm D sao cho MA = MD .

a) Chứng minh : ∆ ABM =∆ DCM .
b) AB // DC
c) AM ⊥ MC
d) Tìm điều kiện ∆ABC để góc ADC =30 °

User Escrava
by
3.1k points

2 Answers

13 votes
13 votes

Final answer:

To prove that ∆ABM is congruent to ∆DCM, we can use the fact that AB = CD, AM = DM and the fact that the included angles are equal.

Step-by-step explanation:

To prove that ∆ABM is congruent to ∆DCM, we can show that AB = CD, AM = DM, and that the included angle between AB and AM is equal to the included angle between CD and DM.

To show that AB = CD, we can use the fact that AB = AC.

To show that AM = DM, we can use the fact that MA = MD.

Finally, to show that the included angles are equal, we can use the fact that the two triangles share the same base, AC, and the included angles are vertical angles.

User Tahsis Claus
by
3.2k points
18 votes
18 votes
hình nè kdowowndjlwlejrbnenabdbsbnwnwnsnsnjdjww
Bài 2: Cho ∆ABC có AB AC = , M là trung điểm của BC . Trên tia đối của tia MA lấy-example-1
User Jeets
by
3.4k points