Known: as shown in the figure, CE bisects ∠ ACD, ∠ 1 = ∠ B, verification: ab ‖ CE

It is proved that ∵ CE bisects ∵ ACD, ∵ 1 = ∵ 2, ∵ 1 = ∵ B, ∵ 2 = ∵ B, ∥ ab ∥ CE

RELATED INFORMATIONS

1. As shown in the figure, it is known that AB / / CD, CE divide ∠ ACD equally, hand AB to e, ∠ a = 118 °, please fill in the reason for ∠ 2 = 31 °
2. In △ ABC, Sina * SINB = cos ^ 2 (C / 2), C = 4, C = 40 ° to find the value of A
3. If ∠ BDC = α + 2 / 3 ∠ a, α is obtained
4. Known: as shown in the figure, ∠ abd = ∠ DBC, ∠ ACD = ∠ DCE. (1) if ∠ a = 50 °, find the degree of ∠ D; (2) guess the relationship between ∠ D and ∠ a, and explain the reason; (3) if CD ‖ AB, judge the relationship between ∠ ABC and ∠ a
5. If ∠ BDC = x + 2 / 3 ∠ a, find the degree of X?
6. In the parallelogram ABCD, AE bisection ∠ DAB intersects DC with E, BF bisection ∠ ABC intersects DC with F, DC = 8cm, ad = 3cm, find the length of De, DF and FC RT
7. It is known that in △ ABC, e and F are the midpoint of AB and AC respectively, CD bisects ∠ BCA and intersects EF with D Verification: ad ⊥ DC Why AF = CF = EF, ADC = 90
8. As shown in the figure, in △ ABC, points E and G are on BC and AC respectively, CD ⊥ AB and ef ⊥ AB, and the perpendicular feet are D and f respectively (1) Is CD parallel to ef? Why? (2) The degree of ∠ ACB can be calculated when ∠ 1 = 2, ∠ 3 = 105 ° is known
9. As shown in the figure, in the triangle ABC, < a = 55 ° and H is the intersection of high BD and EC, then < BHC=
10. It is known that, as shown in the figure, in △ ABC, ∠ ABC = 66 ° and ∠ ACB = 54 ° be and CF are the heights of AC and AB on both sides, and they intersect at point h. calculate the degree of ∠ Abe and ∠ BHC
11. As shown in figure a, CE / / AB, so ∠ 1 = 2 = B, so ∠ ACD = 1 + ∠ 2 = a + B, which is a useful conclusion, In the quadrilateral ABCD of figure B, do AE / / BC to intersect DC with e through A. if you have this conclusion, find the degree of ∠ a + ∠ B + ∠ C + ∠ D Figure a http://hiphotos.baidu.com/yalijudy/pic/item/099efed1bbb16a299a50274f.jpg Figure B http://hiphotos.baidu.com/yalijudy/pic/item/6750e5f54b044b34bd3109e2.jpg
12. AE bisection BAC.CE Divide ∠ ACD equally (1) if AB / / CD, judge whether △ ace is a right triangle, please explain the reason; (2) if ace is a right triangle AE bisection BAC.CE Bisecting ∠ ACD (1) If AB / / CD, judge whether △ ace is a right triangle, please explain the reason; (2) If the triangle ace is a right triangle, judge whether the line AB is parallel to the line CD, please explain the reason
13. As shown in the figure, the high BD and CE of △ ABC intersect at point F. (1) if ∠ abd = 36 °, calculate the degree of ∠ ace; (2) if ∠ a = 50 °, calculate the degree of ∠ BFE
14. Known: as shown in the figure, in △ ABC, ab = AC, ad bisects ∠ BAC, CE ⊥ AB in E, intersects ad in F, AF = 2CD, find the degree of ∠ ace
15. As shown in the figure, in the isosceles triangle ABC, ∠ B = 90, ab = BC = 4cm, point P moves from point a to B at the speed of 1m / s, At the same time, point Q moves from point B to point C at a speed of 2 m / s (1) Which point will arrive first? (2) Let the area of triangle ACB be Y1 and the area of triangle qAB be Y2 after X minutes (3) When the moving time is in what range: (1) the area of triangle PCB is larger than that of triangle; (2) the area of triangle PCB is smaller than that of triangle qAB? Picture too late to pass, sorry!
16. As shown in the figure, in △ ABC, be bisects ∠ ABC, de ‖ BC, ∠ Abe = 35 °, then ∠ DEB=______ Degree, ∠ ade=______ Degree
17. As shown in the figure, it is known that de ∥ BC, DF and be are divided into ∥ ade and ∥ ABC equally, and it is proved that ∥ FDE = ∥ DEB
18. As shown in Figure 5, it is known that in the triangle ABC, AB is greater than AC, the bisector of angle B and the bisector of the outer angle of angle c intersect at D and DF, and BC intersects AB and AC at f and e respectively Question: explain BF = EF + CE.
19. It is known that in the triangle ABC, AB is greater than AC, the bisector of angle B intersects d with the bisector of the outer angle of angle c, DF parallels BC, and AB and AC intersect F and e respectively BF=EF+CE.
20. In the known triangle ABC, the bisector of angle ABC and the bisector of angle ACB intersect at point F, make DF \ \ BC through point F, intersect AB at point D, intersect AC at point E Then: (1) how many isosceles triangles are there? Why? (2) what is the relationship between BD, CE and de? Please prove