Triangle ABC, de parallel BC, known: ad = 10, BD = 5, EC = 4, what is AE -- I'm confused. Help

Triangle ABC, de parallel BC, known: ad = 10, BD = 5, EC = 4, what is AE -- I'm confused. Help

Because De is parallel to BC, triangle ABC is similar to triangle ade, so ad / BD = AE / CE 10 / 5 = AE / 4 AE = 8

D. E are two points on AB and AC respectively, and ad = 4, BD = 2, AC = 8. If the triangle AED is similar to ABC, calculate the length of AE,

1
∵△AED∽△ABC
∴AE：AB=AD：AC
That is AE: 6 = 4:8
∴AE=3
two
∵△AED∽△ABC
∴AE：AC=AD：AB
That is AE: 8 = 4:6
∴AE=16/3

If AB = 2, AC = 4, then the value range of ad is ()
A. AD＜6B. AD＞2C. 2＜AD＜6D. 1＜AD＜3

Extend ad to e, make ad = De, connect be and CE, ∵ ad = de ∵ ad is the middle line on BC side in △ ABC ∵ BD = DC ∵ quadrilateral ABEC is parallelogram ∵ be = AC = 4 ∵ in △ Abe: be-ab < AE < Be + AB, that is, 2 < 2ad < 6 ∵ 1 < ad < 3, so D is selected

In △ ABC, AC = 5 and midline ad = 7, then the value range of AB side is______ ．

Extend ad to e to make de = ad, connect be, ∵ D is the midpoint of BC, ∵ CD = BD