Question

已知线段AB,在AB的延长线上取一点C,使BC=3AB,在BA的延长线上取一点D,使DA=3分之2,E是DB的中点...

Answer 1

CD=168cm, 已知线段AB,在AB的延长线上取一点C,使BC=3AB,在BA的延长线上取一点D,使DA=3分之2,E是DB的中点,且EB=30cm,求线段DC的长

∵AD=3/2AB ,∴DB=3/2AB+AB=5/3AB , EB=1/2DB=1/2 × 5/3 AB =5/6 AB =30---- > AB=36

DB=5/3AB =5/3 × 36 = 60,BC=3AB=3×36=108 ,∴ CD= BC+DB+108+60=168cm