So ∠BCE=∠DFC
Because DC
So ∠BEC=∠DCF
So △BEC∽△DCF (angle)
So be/DC = BC/df (1)
And because the quadrilateral ABCD is a diamond, and ∠ A = 60.
So △ABD and △BCD are equilateral triangles.
So AB=AD=BD=BC=CD.
Therefore, in equation ①, DC can be replaced by BD, and BC can be replaced by BD, which gives
BE/BD=BD/DF ②
Because △ABD is an equilateral triangle,
So ∠ABD=60, ∠ADB=60.
So ∠DBE=∠BDF= 120
Combining equation ②
You can get △BED∽△BDF (corner edge)
So ∠ bed =∠DBF
And because ∠BDE=∠BDH (male * * * angle)
So △ bed ∽△BHD (angle)
So BD/DH=DE/BD
BD? =DH DE
Question 1: Material 3? Material 5
Question 2: A book, like a lamp, guides us into another splendid life journey.
Question 1: Analysis of test questions: Ac