(1) if EF = 5cm, then AB = --- (2) what's the difference between AF and de Please help··

(1) if EF = 5cm, then AB = --- (2) what's the difference between AF and de Please help··

AB=10cm

In △ ABC and △ def, a = D = 60 °, ab = 3cm, BC = 5cm, de = 2.5cm, EF = 1.5cm
So are the two triangles similar
Based on

Not necessarily
Because the angle between AB and BC is B, and the angle between de and EF is e
The two angles are not necessarily equal
So it's not necessarily the same

As shown in the figure, the ground deformation of triangle ABC is BC = a, height ad = h. rectangle efgh is connected to triangle ABC, where E and F are on AC and ab respectively, G and H are on BC, EF = 2fg
Find the perimeter of a rectangle

6ah/（2h+a）

If EF = 2fg, BC = a, triangle ABC, G and H are on BC
If EF = 2fg, BC = a, height ad = h of triangle ABC, find the side length FG of rectangle efgh

Let ad intersect EF with O
Efgh is a rectangle
∴EF∥GH(BC)
∴△AEF∽△ABC
∴EF/BC=AO/AD
∵EF=2FG
AO=AD-FG
∴2FG/a=(h-FG)/h
FG=ah/(2h+a)