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1.题目呈现.(2013.天津第18题)如图1,将△ABC放在每个小正方形的边长为1的网格中,点A、B、C均落在格点上.(Ⅰ)△ABC的面积等于(Ⅱ)若四边形DEFC是图1△ABC中所能包含的面积最大的正方形,请你在如图所示的网格中,用直尺和三角尺画出该正方形,并简要说明画图方法(不要求证明).本题旨在考查位似变换、三角形的面积以及正方形的性质,作出正确的图形是解本题的关键亦是难点.第18题为填空题中的压轴题,以图形变换为核心
(2013. Tianjin No. 18) As shown in Figure 1, △ ABC is placed in the grid with each side of a small square with a length of 1, and points A, B and C fall on the grid. Ⅰ) The area of △ ABC is equal to (Ⅱ) If the quadrilateral DEFC is the square with the largest area that can be contained in △ ABC, draw the square with a ruler and a ruler in the grid as shown , And a brief description of the drawing method (does not require proof.) The purpose of this test is to examine bit-like transformation, the area of the triangle and the nature of the square, to make the correct graphics is the key to solve the problem is difficult. Title, graphic transformation as the core