As shown in the figure, in ladder ABCD, ab ‖ DC, ab ⊥ BC, e are the midpoint of AD, AB + BC + CD = 6, be = 5, then the area of ladder ABCD is equal to () A. 13B. 8C. 132D. 4

As shown in the figure, if passing through point E and making EF ‖ AB intersecting BC at point F, then BF = 12bc, EF = 12 (AB + CD) = 12 (6-bc), and ∵ ab ⊥ BC, ∵ EF ⊥ BC, ∵ in RT △ BFE, ef2 + BF2 = be2. ∵ [12 (6 − BC)] 2 + (12bc) 2 = (5) 2, that is, bc2-6bc + 8 = 0, the solution is BC = 2 or BC = 4, then EF = 2 or EF = 1, ∵ s ladder ABCD = EF · BC = 4

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1. In diamond ABCD, point E is on diagonal AC, point F is on the extension of BC, EF = EB, EF and CD intersect at point G How to prove that triangle EGC is similar to triangle DGF after connecting DF
2. In ladder ABCD, ad ‖ BC.AC Intersection with BD at point E, if the area of △ AED is a, △ BEC area B, calculate the area of trapezoid ABCD
3. The area of trapezoidal ABCD is 45 square centimeters, and its height is 6 centimeters. AC and BD intersect at point e. the area of AED is 5 square centimeters,
4. In the parallelogram ABCD, BC = 2Ab, e is the midpoint of BC, then ∠ AED=______ ．
5. ）(1) As shown in Figure 10, in the parallelogram ABCD, BC = 2Ab, e is the midpoint of the BC side, and the degree of ∠ AED is calculated. (2) as shown in Figure 11, e is the square ab ）(1) As shown in Figure 10, in the parallelogram ABCD, BC = 2Ab, e is the midpoint of BC side, and the degree of ∠ AED is calculated (2) As shown in Figure 11, e is a point in the square ABCD, and △ Abe is an equilateral triangle. Think about the relationship between ∠ CED and ∠ CEB, and explain the reason (3) As shown in Figure 12, the height and perimeter of the isosceles trapezoid ABCD are determined by the upper bottom ad = 1, the lower bottom BC = 3 and the diagonal AC ⊥ BD file:///C:/Documents%20and%20Settings/Administrator/Local%20Settings/Temporary%20Internet%20Files/ Content.IE5/3YP2UMUP/image035%5B1%5D .jpg
6. In the parallelogram ABCD, BC = 2Ab, e is the midpoint of BC, then ∠ AED=______ ．
7. In the parallelogram ABCD, BC = 2Ab, e is the midpoint of BC, then ∠ AED=______ ．
8. In the parallelogram ABCD, BC = 2Ab, e is the midpoint of BC, then ∠ AED=______ ．
9. In a parallelogram ABCD, a straight line AF passing through point a intersects point BC at point E, and a DC extension line intersects point F. try to explain that the area of △ ABF and △ ade is equal
10. In the parallelogram ABCD, a straight line AF passing through point a intersects point BC and point E, and a DC extension line intersects point F, which indicates that the areas of △ ABF and △ ade are equal thinking Yes
11. What is the ratio of s △ AED to s ladder ABCD if ab ‖ DC and point e are the midpoint of waist BC in ladder ABCD
12. If the quadrilateral ABCD is a parallelogram, e and F are the points on the extension line of AC and Ca respectively, and CF = AE, what is the relationship between BF and de? Please explain the reason (2) As shown in Figure 14, in trapezoidal ABCD, ab ‖ CD, AC and BD intersect at point O. if OA = ob, try to judge the shape of trapezoidal ABCD and explain the reason
13. As shown in the figure, the quadrilateral ABCD is a parallelogram, and the points E and F are the points on the sides of AD and BC respectively, and AE = cf. the following are proved: (1) the △ Abe ≌ △ CDF; (2) the quadrilateral BEDF is a parallelogram
14. As shown in the figure, in the trapezoidal ABCD, AD / / BC, ab = CD, e is the midpoint of BC It's in the mathematics evaluation manual of the ninth grade volume I of Jiangsu Education Press.
15. As shown in the figure, in the trapezoidal ABCD, ab ‖ CD is known, and point E is the midpoint of BC. If the area of △ DEA is S1 and the area of trapezoidal ABCD is S2, then the quantitative relationship between S1 and S2 is______ ．
16. As shown in the figure, in the right angle trapezoid ABCD, ∠ C = 90 °, ad ‖ BC, AD + BC = AB, e is the midpoint of CD. If ad = 2, BC = 8, calculate the area of △ Abe
17. As shown in the right figure, in the trapezoidal ABCD, AD / / BC, the area of triangle Abe is 30 square centimeters, EC = 2ae, calculate the area of trapezoidal ABCD The figure is trapezoid with two diagonals The order is (from left to right) ADB The focus is e
18. As shown in the figure, in the parallelogram ABCD, AC and BD intersect at point O, e is the outer point of the parallelogram ABCD, EA ⊥ EC, ed ⊥ be
19. 1. Given that e is the midpoint of the edge BC of the parallelogram ABCD and EA = ed, it is proved that the four deformed ABCD is a rectangle 2. The bisector of an inner corner of a rectangle divides an edge of the rectangle into 6cm. What is the length of the bisector of the inner corner of the rectangle when it is 8cm? 3. In rectangular ABCD, ab = 2BC, e is a point on CD, and AE = AB, what is the degree of ∠ EBC? 4. AC is the diagonal of square ABCD, AE bisects ∠ BAC, proving: ab + be + AC 5. In rectangular ABCD, M is the midpoint of AD, CE ⊥ BM, the perpendicular foot is e, ab = 4cm, BC = 4 レ 2cm, find the length of Ce (Note: 4 レ 2 →→→ 4 times root 2) Wealth, No picture. Thank you
20. Known: as shown in the figure, in the isosceles trapezoid ABCD, ab = CD, ad ‖ BC, e is a point outside the trapezoid, and EA = ed, prove: EB = EC