As shown in the figure, in △ ABC, ad bisects ∠ BAC, de ‖ AC, EF ‖ BC, ab = 15, AF = 4, then de=______ .
Let ed = x, then AC = 4 + X. ∵ ad bisector ∠ BAC. From the bisector theorem of triangle inner angle, we get ABAC = bddc = 154 + X and deca = bdbc. ∵ XX + 4 = 1519 + X, and the solution is x = 6 (x = - 10, rounding off), so the answer is 6
RELATED INFORMATIONS
- 1. Finding AF / ad = ad / AB in triangle ABC by de / / BC EF / / CD
- 2. As shown in the figure, in triangle ABC, De is parallel to BC, EF is parallel to CD
- 3. On the isosceles △ ABC, ab = AC, passing a point E on BC, do a straight line DF, intersect AB with D, intersect AC with F, and prove de / EF = dB / CF
- 4. The relationship between EF and be can be obtained by taking m as a 30 ° angle, intersection AB with E, intersection CA extension line with F
- 5. In the triangle ABC, BD is perpendicular to AC at point D, CE is perpendicular to ab at point E, BD and CE intersect at point h, ad = DH = 1, CD = 5, find the area of triangle ABC. If you can't send the graph, please draw it by yourself. The top vertex is a, and the bottom is left B and right C
- 6. As shown in the figure, ⊿ ABC is an isosceles triangle, ∠ ABC = 90? Therefore, B = 10, D is a point outside ⊿ ABC, connecting AD.BD If point h, AC ⊥ abd is an equilateral triangle, find the length de: (2) if BD = AB, and DH BH = 3 / 4
- 7. As shown in the figure, it is known that ad, be and CF are respectively the heights of the three sides of △ ABC, h is the perpendicular, and the extension line of ad intersects the circumscribed circle of △ ABC at point G
- 8. As shown in the figure, it is known that ad, be and CF are respectively the heights of the three sides of △ ABC, h is the perpendicular, and the extension line of ad intersects the circumscribed circle of △ ABC at point G
- 9. In the triangle ABC, AB is equal to 13, BC = 10, and the middle line ad on the side of BC = 12. Is the triangle ABC an isosceles triangle
- 10. Ad is the height of triangle ABC, AB is equal to 10, ad is equal to 8, BC is equal to 12, triangle ABCD is isosceles triangle
- 11. As shown in the figure, in △ ABC, ab = AC, D, e and F are on three sides respectively, and be = CD, BD = CF, G is the midpoint of EF
- 12. In triangle ABC, CF is perpendicular to AB and be is perpendicular to AC and E. m is the midpoint of BC, BF = 5 and BC = 8. Can you determine the perimeter of triangle EFM?
- 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______ .
- 14. 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______ .
- 15. Triangle ABC and triangle BDE are equilateral triangles. This paper proves that: (1) triangle ABC is equal to triangle CBD (2) AE = De Please, hurry up
- 16. 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
- 17. 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______ .
- 18. 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
- 19. 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
- 20. 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?