Current location - Training Enrollment Network - Mathematics courses - In 2009, the senior high school entrance examination in Weifang, Shandong Province, solved the 20 th problem of mathematics.
In 2009, the senior high school entrance examination in Weifang, Shandong Province, solved the 20 th problem of mathematics.
Method1; You can draw parallel lines on the finish line.

point out

The intersection f makes FM parallel to AC and intersects BC at m.

Then it is proved that the triangular FMD is similar to the triangular ECD.

Method 2; Connecting AD, because CD=BC, it is easy to know that C is the midpoint of BD, and because F is the midpoint of AB, AC and DF intersect with E, so E is the center of gravity of triangle ABD, which can be easily found by using the nature of the center of gravity.

Method 3; Connect AD and FC, and solve the problem by using the property of neutral line.

The final result of the above three methods is 2 to 3.