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As shown in the figure, known quadrilateral ABCD is isosceles trapezoid, CD ‖ Ba, quadrilateral aebc is parallelogram
It is proved that ∵ quadrilateral ABCD is isosceles trapezoid, CD ∥ Ba, quadrilateral aebc is parallelogram ∥ ad = BC = AE, BD = AC = be, ab = AB, ≌ AEB ≌ ADB (SSS) ∥ abd = ∩ Abe
As shown in the figure, in the isosceles trapezoid ABCD, ab ‖ CD, AC and BD are diagonals. If △ abd is folded down along AB to the position of △ Abe, the shape of quadrilateral aebc is ()
A. Parallelogram B. isosceles trapezoid C. rectangle D. diamond
The quadrilateral aebc is a parallelogram, ∵ ABCD is an isosceles trapezoid, ab ∥ CD, AC, BD are diagonals, ∵ ad = BC, AC = BD, ∵ abd is folded along AB to ∵ Abe, AE = ad, ∵ AE = BC, AC = be, ∵ quadrilateral aebc is a parallelogram
In the isosceles trapezoid ABCD, AB is parallel to CD, AC and BD are diagonals, the triangle abd eye AB is folded down to get the triangle AEB, what is the special shape of the quadrilateral aebc
I think it's a rectangle, but I can only prove parallelogram.
AE=AD=BC,BE=BD=AC
A quadrilateral aebc is a parallelogram
As shown in the figure, the quadrilateral ABCD is a parallelogram, the point E is on the extension line of the side Ba, CE intersects ad with F, ∠ ECA = ∠ D
It is proved that the ∵ quadrilateral ABCD is a parallelogram, ∵ BC = ad, CD ∥ AB, ad ∥ BC, ∵ d = ∵ DAE = ∥ B, ∵ ECA = ∵ D, ∵ ECA = ∥ B, ∵ e = ∥ e,
RELATED INFORMATIONS
- 1. ABCD is trapezoid, ab ∥ CD, ADBE is parallelogram, the extension line of AB intersects EC in F Can s △ BCE be one third of s ladder ABCD? If not, explain the reason; if yes, find out the relationship between AB and CD The answer is yes. How can we prove it
- 2. As shown in the figure, e is the outer point of parallelogram ABCD, and ab ⊥ EC, be ⊥ ed, is parallelogram ABCD a rectangle?
- 3. In the parallelogram ABCD, ad = a, be parallel to AC, De, the length line of AC intersects F and be intersects E
- 4. In the triangular pyramid p-abc, △ PAC and △ PBC are equilateral triangles with side length √ 2, ab = 2, O and D are the midpoint of AB and Pb respectively 1) Verification: plane PAB ⊥ plane ABC (2) Find the volume of p-abc of triangular pyramid (3); OD is parallel to PAC
- 5. If O is a point in the plane of triangle ABC and iob-oci = iob + oc-2oai is satisfied, then the shape of triangle ABC is All the letters in the question represent vectors
- 6. It is known that the edge length of regular tetrahedron oabc is equal to 1, m and N are the midpoint of edges OA and BC respectively. Let vector OA = vector a, vector ob = vector B and vector OC = vector C (1) Finding the solution of vector m with respect to base (a, B, c) (2) Finding the length of line segment Mn (1) Finding the solution of the vector Mn with respect to the base (a, B, c) (2) Finding the length of line segment Mn
- 7. In a tetrahedral o-abc with edge length 2, the square of (OA vector + ob vector + OC vector) is The answer is 24
- 8. Take points m and N on the convenient OA and ob of △ OAB so that om: OA = 1:3 and on: OB = 1:4. Let an and BM intersect at point P, and let OA = A and ob = B Let a and B denote the vector Op
- 9. Given the vector 0P = (2,4), OA = (2,6), OB = (5,1), let m be a point on the line OP, then the minimum value of ma * MB
- 10. Vector OA = (1,0) ob = (0,1) om = (T, t) (t belongs to R) (1) if three points of ABM are collinear, find the value of T (2) when t takes what value, vector Ma
- 11. Given that point P is a point in the plane of triangle ABC and satisfies 3PA + 5pb + 2pc = 0, let the area of ABC be s, then the area of triangle PAC is
- 12. In Δ ABC, P is a point on the edge of BC, and | BP | = 2 | PC |, and D is the midpoint of AC. AP and BD intersect at point O. we use vectors AB and AC to represent vector Ao Use the solution of the three points collinear; a = λ B + (1 - λ) C
- 13. As shown in the figure, in △ ABC, CF ⊥ AB is in F, be ⊥ AC is in E, M is the midpoint of BC, EF = 5, BC = 8, then the perimeter of △ EFM is () A. 13B. 18C. 15D. 21
- 14. Given the vector a = (2. K). B = (3. 4), and a is perpendicular to B, then the real number k =?
- 15. Given the vector a = (k, 1), B = (6, - 2), if a is parallel to B, then the real number k = 1___ ．
- 16. If the image of the function y = a ^ (2x + b) + 1 (a > 0, a ≠ 1, B ∈ R) passes the fixed point (1,2), then what is B?
- 17. A (1.1), F 1 = (3.4), F 2 = (2. - 5). F 3 = (3.1), then the end point coordinate of the resultant force The options are (9,0) (0.9) (1.9) (9.1) In fact, I personally feel that the options are not right
- 18. As shown in the figure, a wooden block placed on a horizontal table is subjected to three forces in the horizontal direction, namely F1, F2 and friction. The wooden block is in a static state, where F1 = 10N and F2 = 4N A. If the force F1 is removed, the resultant force of the block in the horizontal direction may be 2Nb. If the force F1 is removed, the resultant force of the block in the horizontal direction must be 0C. If the force F2 is removed, the resultant force of the block in the horizontal direction may be 2nd. If the force F2 is removed, the resultant force of the block in the horizontal direction must be 0
- 19. As shown in the figure, a, B, C three objects stacked together, in the horizontal force F1 = F2 = 5N, at the same speed on the horizontal table uniform motion How much friction does object B have on a? How much friction does object B have on C? How much friction does the ground have on C?
- 20. An object with a mass of 1kg is subjected to two forces F1 = 3N and F2 = 4N respectively. If F1 and F2 are perpendicular to each other, then the acceleration of the object is A. 3 M / S ^ 2 b.4 M / S ^ 2 C.5 M / S ^ 2 d.7 M / S ^ 2