![](data:image/svg+xml;utf8,<svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" viewBox="0 0 72 71" width="72"></svg>)
It is known that the perimeter of the parallelogram ABCD is 50cm, the diagonals intersect at point O, the perimeter of △ AOB is 5cm longer than that of △ BOC, and the lengths of AB and BC are calculated No picture
AB + BC = 25 copies, △ AOB perimeter - △ BOC perimeter = 5, ab-bc = 5
Ab-bc = 5
So if we add two to one, we get 2Ab = 30, then we get AB = 15, BC = 10
In the parallelogram ABCD, De is perpendicular to AB and E, BF is perpendicular to AD and F
1. Prove that AD / de = AB / BF
2. The perimeter of parallelogram ABCD is 12, ad: de = 5:2. Calculate the value of de + BF
(1) rt ⊿ ade ⊿ RT ⊿ AFB, AD / AB = de / BF, that is, AD / de = AB / BF
(2) let de = 2x. Then ad = 5x. AB = 6-5x
∵AD/AB＝DE/BF.∴DE/（DE+BF）＝AD/（AD）+AB）.
DE+BF＝（AB+AD）DE/AD＝[（6-5x）+5x]×2x/5x＝12/5＝2.4
RELATED INFORMATIONS
- 1. Known: as shown in the figure, the quadrilateral ABCD is a parallelogram, e and F are two points on the straight line BD, and de = BF. (1) prove: AE = CF; (2) connect AF and CE, then is the quadrilateral afce a parallelogram?
- 2. The diagonals AC and BD of parallelogram ABCD intersect at O, e and F, which are two points on DB, and de = BF I'm sorry to trouble you to copy it,
- 3. If the perimeter of parallelogram is 48mm and the diagonal intersects o, the perimeter of triangle AOB is 4mm longer than that of triangle BOC, then the lengths of AB and BC are equal to?
- 4. It is known that the perimeter of a parallelogram is 20 cm. A diagonal divides it into two triangles with a perimeter of 16 cm. How many cm is the diagonal?
- 5. A circle with a circumference of 6.28dm can be divided into several equal parts to form a parallelogram. The bottom of the parallelogram is equivalent to______ Yes______ The height of a parallelogram is equal to______ Yes______ cm．
- 6. If the perimeter of parallelogram ABCD is 32,5ab = 3bC, the value range of diagonal AC is ()
- 7. As shown in the right figure, in the parallelogram ABCD, we know that ad = 8 and perimeter is equal to 24, then we find the lengths of the other three sides
- 8. As shown in the figure, ▱ the diagonal lines AC and BD of ABCD intersect at point O, point E is the midpoint of CD, and the perimeter of △ abd is 16cm, then the perimeter of △ DOE is______ cm．
- 9. In triangle ABC, angle B = angle c = 36 degrees, angle ade = angle ade = 72 degrees, then the number of isosceles triangles in the graph is?
- 10. For a piece of land as shown in the figure, ad = 12M, CD = 9m, ∠ ADC = 90 °, ab = 39m, BC = 36m, calculate the area of this land
- 11. As shown in the figure, in ▱ ABCD, the diagonal AC = 21cm, be ⊥ AC, the perpendicular foot is e, and be = 5cm, ad = 7cm, then the distance between AD and BC is______ cm．
- 12. There is a little E in the quadrilateral ABCD,
- 13. In trapezoidal ABCD, AD / / BC, ∠ ABC = 60 °, DCB = 30 °, ab = 4, BC-AD is calculated
- 14. In trapezoidal ABCD, ad ∥ BC, ab = 4, BC = 9, CD = 5, Da = 6. (1) prove ab ⊥ BC; (2) find the area of trapezoidal ABCD
- 15. As shown in the figure, in trapezoidal ABCD, ∠ d = 90 ° and M is the midpoint of ab. if cm = 6.5 and BC + CD + Da = 17, the area of trapezoidal ABCD is () A. 20B. 30C. 40D. 50
- 16. In the trapezoidal ABCD, ab = CD, e is the midpoint of AD
- 17. As shown in the figure, in trapezoidal ABCD, ad is parallel to BC, AF is vertical, BC and points F, m are the midpoint of CD, angle B is 45 degrees, AF is 4, EF is 7 Find ABCD area
- 18. It is known that in trapezoidal ABCD, ad is parallel to BC, AB is parallel to de, AF is parallel to DC, e and F are on edge BC As shown in the figure, in the trapezoidal ABCD, ad ‖ BC, ab ‖ De, AF ‖ DC, e and F are on the side BC, and the quadrilateral aefd is a parallelogram (1) What is the equivalent relationship between AD and BC (2) When AB = DC, it is proved that the quadrilateral aefd is a rectangle I want to prove that the process is not an equation
- 19. As shown in the figure, in the square ABCD, point P is a point on the diagonal AC, PE ⊥ AB, PF ⊥ BC, and the perpendicular feet are points E and f respectively. If the perimeter of the square ABCD is 8cm, then the perimeter of the quadrilateral EBFP is______ cm．
- 20. In the isosceles triangle ABCD, ab = AC, ∠ a = 36 ° and BD is the square of ∠ ABC, then calculate AD / AC