Bài tập 1: Điền vào chỗ trống các tính từ để hoàn chỉnh câu

1.The weather is colder today than it was yesterday.

2.She is the most smart person in the room.

3.The pizza was more delicious than the hamburgers.

4.This is the most interesting book I’ve ever read.

5.The tiger is more dangerous than the lion.

6.My cat is more playful than my dog.

7.That was the most difficult test I’ve ever taken.

8.The sunrise most beautiful than the sunset.

9.Her dress is more expensive than mine.

10.This restaurant has gooder food than the one downtown.

11.The river is more shallow than the lake.

12.The movie was more exciting than the trailer.

13.She is most friendly person I know.

14.The summer is hoter than the spring.

15.His car is faster than hers.

16.That was the most annoying noise I’ve ever heard.

17.The marathon was more tiring than I expected.

18.My grandmother’s stories are more interesting than mine.

19.This puzzle is more challenging than the one we did last night.

20.The mountain is most high in the winter.

Nối B với N

-Xét hai tam giác BNC và ABC có

Chieuf cao chung hạ từ đỉnh B xuống đáy AC

=> Đáy NC=1/3 AC

=>S BNC = 1/3 S ABC

C/m tương tự ta đc S CMN=1/2S ABC

Ta có : S BNC= 1/3 S ABC

           S CMN= 1/2 S BNC

=> CMN= 1/3 x 1/2 = 1/6 ABC

S ABC = 4,5 x 1/6 = 27 cm

Vậy S ABC = 27 cm