Known: as shown in the figure, ab = AC, ∠ abd = ∠ ACD

It is proved that: connect BC. ∵ AB = AC (known), ∵ AB = 2 (equilateral and equal angle), abd = ∵ ACD (known), ∵ abd - ∵ 1 = ∵ ACD - ∵ 2 (equality operation property). That is, ∵ 3 = ∵ 4. ∵ BD = DC (equilateral and equal angle)

RELATED INFORMATIONS

1. As shown in the figure, given AB = AC, DB = DC, try to explain ∠ abd = ∠ ACD
2. As shown in the figure, AC ⊥ CB, BD ⊥ CB, ab = DC, verify ∠ abd = ∠ ACD
3. As shown in the figure, in △ ABC, ∠ C = 90 °, ad is the bisector of ∠ BAC, de ⊥ AB is on e, f is on AC, DB = DF As shown in the figure, in △ ABC, ∠ C = 90 °, ad is the bisector of ∠ BAC, de ⊥ AB is on e, f is on AC, DB = DF
4. It is known that △ ABC, ad bisects ∠ BAC and intersects BC with D, DB = DC. Prove that △ ABC is an isosceles triangle. Prove that: ∵ DB = DC ∵ ad is the middle line of △ ABC ∵ ad bisects ∠ BAC and intersects BC with D ∵ ad is also the angle bisector of ∠ BAC in △ ABC. Is ∵ ABC an isosceles triangle?
5. It is known that in △ ABC, D is any point on the edge of ab Please write down the steps clearly
6. As shown in the figure, in △ ABC, ab = AC, ∠ BAC = 36 °, CD bisection ∠ ACB intersects AB at point D, AE parallels DC intersects BC extension line at point E, if DB = 2, CD = 3, AE = how much?
7. As shown in the figure, given that point F is a point on the extension line of the edge BC of △ ABC, DF ⊥ AB is at D, intersection AC is at e, and ∠ a = 56 °, f = 31 °, calculate the degree of ∠ ACB
8. As shown in the figure, given that point E is on the edge ab of △ ABC, point D is on the extension line of Ca, and point F is on the extension line of BC, what is the size relationship between ∠ ACF and ∠ D? Please give reasons
9. As shown in the figure, △ ABC, ab = AC, ∠ BAC = 110 °, ad is the middle line on the side of BC, and BD = be, then ∠ AED degree is______ ．
10. Triangle ABC is an equilateral triangle, D is the midpoint of side AB, de and BC are perpendicular, and the area of triangle BDE is 5 square centimeters. Find the area of triangle ABC
11. As shown in the figure, ad bisects ∠ BAC, de ⊥ AB in E, DF ⊥ AC in F, and DB = DC, proving: EB = FC
12. As shown in the figure, ad bisects ∠ BAC, de ⊥ AB in E, DF ⊥ AC in F, and DB = DC, proving: EB = FC
13. As shown in the figure, ad bisects ∠ BAC, de ⊥ AB in E, DF ⊥ AC in F, and DB = DC, proving: EB = FC
14. As shown in the figure, Bo = OC, ab = DC, BF ‖ CE, and a, B, C, D are on the same line
15. Given that f (x) = - X & sup3; - x + 1, (x belongs to R), it is proved that y = f (x) is a decreasing function on the domain of definition, and there is at most one real value x satisfying the equation f (x) = 0
16. The students went boating in the park. There were 60 people, and 16 boats were hired. Each big boat took 4 people, and each small boat took 3 people?
17. When many is an indefinite pronoun as the subject, is the predicate singular or plural?
18. Dad's words remind me of many things in the past. That's not right. It's a sick sentence What is your understanding of harmony? What is a close synonym?
19. When drawing the small signal equivalent circuit of amplifying circuit, the DC power supply in the circuit is often short circuited, that is, the positive end of DC power supply VCC is regarded as DC positive potential and AC negative potential How to understand this? In addition, why the sine wave signal generator with continuous frequency variation is often selected as the experimental and test signal source of amplification circuit
20. As shown in the figure, in rectangular ABCD, it is known that ab = 3aD, e and F are two bisectors of AB, AC and DF intersect at point G, and an appropriate rectangular coordinate system is established