As shown in the figure, triangle ABC is an equilateral triangle, D is a point on BC, angle ade = 60 degrees, CE bisects the outer angle ACF of triangle ACB, proving: ad = De

As shown in the figure, triangle ABC is an equilateral triangle, D is a point on BC, angle ade = 60 degrees, CE bisects the outer angle ACF of triangle ACB, proving: ad = De

It is proved that: to connect AE, let AC and de intersect at O ∵ ⊿ ABC be an equilateral triangle ∵ ACB = 60 ∵ 186;, then ∵ ACF = 120 ∵ 186; ∵ CE bisection ∵ ACF ∵ ace = 60 ∵ 186; = ∵ ade and ∵ AOD = ∵ EOD ∵ AOD ∵ EOC (AA ⊿ AO / EO = do / Co, that is, AO / do = EO / CO and ∵ AOE = doc ∵ AOE