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1.(义乌)如图1,在△ABC中,点D是BC的中点.作射线AD.在线段AD及其延长线上分别取点E、F,连接CE、BF.添加一个条件,使得△BDF≌△CDE,并加以证明.你添加的条件是(不再添加辅助线).提示:DE=DF或CE∥BF等.2.(杭州)如图2,平面直角坐标系中有四个点,它们的横纵坐标均为整数.若在此平面内移动点A,使得这四个点构成的四边形是轴对称图形,并且点A的横纵坐标仍是整数,则移动后点A的坐标为____.提示:点A的坐标可以是(-1,1)或(一2,一3)或(0,2)或(-2,-2).3.(绍兴)如图3,AB∥CD.以点A为圆心,小于AC的长为半径作圆弧,分别交AB、AC于E、F两点.
1. (Yiwu) As shown in Fig. 1, in △ ABC, point D is the midpoint of BC. For ray AD, take points E and F on segment AD and its extension respectively, connect CE and BF. Add a condition, So that △ BDF ≌ △ CDE, and to prove that you add the condition is (no longer add auxiliary line.) Hint: DE = DF or CE ∥ BF etc. (Hangzhou) Figure 2, Cartesian coordinate system Four points, their horizontal and vertical coordinates are integers.If this point in the plane moving A, making the four points formed by the quadrilateral axisymmetric graphics, and the horizontal and vertical coordinates of point A is still an integer, the point after the move The coordinates of A are ____. Tip: The coordinates of point A can be (-1,1) or (-2, -3) or (0,2) or (-2, -2) .3. Figure 3, AB //CD. A point as the center, less than AC for the radius of the arc, respectively, to pay AB, AC at E, F two.