SOLUTION: D is a point on the side BC of an equilateral triangle ABC such that DC is equal to 1/4 of BC. prove that AD square is equal to 13 CD esquare
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-> SOLUTION: D is a point on the side BC of an equilateral triangle ABC such that DC is equal to 1/4 of BC. prove that AD square is equal to 13 CD esquare
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Question 982347: D is a point on the side BC of an equilateral triangle ABC such that DC is equal to 1/4 of BC. prove that AD square is equal to 13 CD esquare Answer by mananth(16946) (Show Source):
You can put this solution on YOUR website! .
AD^2= AE^2+DE^2
AE= sqrt(3)AC/2
AE^2= 3AC^2/4
AC=BC
AE^2 = 3BC^2/4
But BC = 4DC
AE^2 = 48DC^2/4
AE^2= 12DC^2
DE^2= (CE-CD)^2
But CE = BC/2
But BC= 4DC
SO CE = 2DC
DE^2= (2DC -DC)^2
= DC^2
