in `Delta ABC ,/_A =2/_B` Prove that `BC^2= AC^2 + AC.AB`

In Delta ABC, AD_|_ BC . Prove that AB^(2) - BD^(2) =AC^(2) -CD^(2)

In an equilateral triangle ABC, AD _|_ BC . Prove that : AB^(2) + CD^(2) = 5/4 AC^(2)

In a Delta ABC, /_ B is an acute-angle and AD bot BC . Prove that: AB^2 + CD^2 = AC^2 + BD^2

In Delta ABC , BD : CD = 3 : 1 and AD _|_ BC . Prove that 2(AB^(2) - AC^(2)) = BC^(2) .

In Fig.6.59, ABC is a triangle in which angleABC<90^@ and AD_|_BC .Prove that AC^2=AB^2+BC^2-2BC.BD .

In figure, AD is a median of a triangle ABC and AM bot BC. Prove that AC ^(2) + AB ^(2) = 2 AD ^(2) + (1)/(2) BC ^(2).

In Delta ABC, "seg" AD bot "seg" BC, DB = 3CD . Prove that: 2 AB^(2) = 2AC^(2) + BC^(2)

In the isosceles triangle ABC, AB=AC and BE is perpendicular to AC from B. Prove that BC^(2) = 2ACxxCE

In triangle ABC , seg AD_|_side BC , B-D-C. Prove that AB^2+CD^2=BD^2+AC^2

In an isosceles Delta ABC , if AC=BC and AB ^(2)= 2AC^(2) then angle C=?