△ABC中,BC>AB>AC,∠ACB=50°,点D、点E是射线BA上的两个点,且满足AD=AC,BE=BC,则∠DCE的度数为____.
一块三角形地,高是36米,底是18米,共收小麦777.6千克,平均每平方米收小麦多少千克?
The place needs a large quantity of water for people to drink.
—Mine.