Question

Cho tam giác ABC  có diện tích  bằng 180 cm^2.. Kéo dài đáy BC về phía  C lấy điểm D sao cho CD bằng 50% BC. Nối A với D. Tính diện tích tam giác ABD?

Answer 1

So sánh hai tam giác ABC và ADC chúng có chung đường cao hạ từ A xuống BD

DC = 50%BC = 1/2 X BC

Vậy diện tích tam giác : ADC = 1/2 ABC = 180 : 2 = 90 cm2

Diện tích tam giác ABD là : 180 + 90 = 270 cm2

Answer 2

270 cm² đó bạn, bài đấy co trong quyển Tự Luyện VIOLYMPIC lên mình làm rồi!!!

Answer 3

270 cm2

Answer 4

270 đó

Answer 5

270 đó cam đoan chuẩn 10000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000%

Answer 6

Bằng 270 cm2

Answer 7

Đúng đó kết quả bằng 270 cm2

Answer 8

270 là đúng 

10000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000%

Answer 9

Ta có :

DC = 1/2 BC =1/2 x BC

vậy diện tích tam giác là :

       ADC = 1/2 ABC =180 : 2 = 90 (cm²)

diện tích tam giác ABD là :

      180 + 90 = 270 (cm²)

                             Đ/S