如图,在一个四边形ABCD中,AC、BD相交于点O.作三角形DBC的高DE,连接AE.若三角形ABO的面积与三角形DCO的面积相等,且DC=17厘米,DE=15厘米,则阴影部分的面积为多少平方厘米?
计算下面各题..
.
计算下面各题.= = == = == = =
= 1﹣= = == = = =
直接写出得数.= = == = == = == = =