Geometry
posted by Jen .
Rectangle ABCD has diagonals AC and BD. E is the point of intersection of the two diagonals. If the area of triangle AEB is 8, what is the area of triangle ACD?

ACD has half the area if the rectangle.
AEB is less than half of the rectangle, and its fraction of the whole depends upon the aspect ratio (AB/BC) of the triangle.
More information is needed to answer the question. 
In a rectangle, the diagonals bisect each other giving you four triangles of equal area.
so triangle ACD = 16 
Whoops! I forgot that equalarea theorem. Thanks again, Reiny.