单选题
In the figure above, square CDEF has area 4. What is the area of △ABF?
In the figure above, square CDEF has area 4. What is the area of △ABF?
【正确答案】
E
【答案解析】[解析] 由正方形CDEF的面积等于4，可知其边长CF=2，在△CFB中，∠CBF=30°，所以BF=2[*]。再由∠FAB=45°可知△FBA是等腰直角三角形，所以其面积[*][*]