△ABC中,BC=a 1)若AD1=1/3AB,AE1=1/3AC,则D1E1=? (2)若D1D2=1/3D1B,E1E2=1/3E1C,则D2E2=? (3)若D2D3=1/3D2要步骤.
来源:学生作业帮助网 编辑:作业帮 时间:2024/07/02 01:33:05
![△ABC中,BC=a 1)若AD1=1/3AB,AE1=1/3AC,则D1E1=? (2)若D1D2=1/3D1B,E1E2=1/3E1C,则D2E2=? (3)若D2D3=1/3D2要步骤.](/uploads/image/z/5482830-30-0.jpg?t=%E2%96%B3ABC%E4%B8%AD%2CBC%3Da+1%29%E8%8B%A5AD1%3D1%2F3AB%2CAE1%3D1%2F3AC%2C%E5%88%99D1E1%3D%3F+%282%29%E8%8B%A5D1D2%3D1%2F3D1B%2CE1E2%3D1%2F3E1C%2C%E5%88%99D2E2%3D%3F+%283%29%E8%8B%A5D2D3%3D1%2F3D2%E8%A6%81%E6%AD%A5%E9%AA%A4.)
△ABC中,BC=a 1)若AD1=1/3AB,AE1=1/3AC,则D1E1=? (2)若D1D2=1/3D1B,E1E2=1/3E1C,则D2E2=? (3)若D2D3=1/3D2要步骤.
△ABC中,BC=a 1)若AD1=1/3AB,AE1=1/3AC,则D1E1=? (2)若D1D2=1/3D1B,E1E2=1/3E1C,则D2E2=? (3)若D2D3=1/3D2
要步骤.
△ABC中,BC=a 1)若AD1=1/3AB,AE1=1/3AC,则D1E1=? (2)若D1D2=1/3D1B,E1E2=1/3E1C,则D2E2=? (3)若D2D3=1/3D2要步骤.
1) 由D1E1/BC = AE1/AC ,即D1E1=a/3
2)因为D1D2=1/3D1B,E1E2=1/3E1C,所以D1D2=2/9AB,E1E2=2/9AC,
那么AE2=AE1+E1E2=1/3AC+2/9AC=5/9AC,
同理D2E2/BC = AE2/AC ,得D2E2=5/9a,
3)同理可做.