【Haichuan Teahouse】Is it easier to calculate when the moving point reaches the end?
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As shown in the figure, the upper base of the right trapezoid ABCD is 2 cm long, and its lower base is 4 cm long. E is a point on AB. The area of triangle AED is 3 square centimeters, and the area of triangle EDC is 8 square centimeters. Find the area of the trapezoid.
This post was last edited by Wang Genrong on 2021-9-3 at 14:30. I misread the question; 30 is incorrect – it should be 15.
The correct answer is 15:hug:
As shown in the figure, the value 3 in the labeled quantity can be determined based on the fact that triangle EAD has an area of 3. Let the red line represent X and the blue line represent Y; by applying the principle of similar triangles together with the fact that the area of triangle EDC is 8, equations can be solved to find that X = 2. (Y doesn’t need to be calculated). The height of the trapezoid is 5, so the area is 15.