" Qin.ABC,AD and BE are altitudes.Prove that "(ar(Delta DEC))/(ar(Delta ABC))=(DC^(2))/(AC^(2))" ."(DC^(2))/(AC^(2))" .In civale "

In Delta ABC,AD and BE are altitudes.Prove that (ar(Delta DEC))/(ar(Delta ABC))=(DC^(2))/(AC^(2))

Delta ABC and Delta BDC are on the same base BC. Prove that (ar(Delta ABC))/(ar(Delta DBC)) =(AO)/(DO)

In right angled triangle ABC,/_A is right angle.AD is perpendicular to the hypotenuse BC.Prove that (Delta ABC)/(Delta ACD)=(BC^(2))/(AC^(2))

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

In triangle ABC, AD is a median. Prove that AB + AC gt 2AD

In triangle ABC, AD is a median. Prove that AB + AC gt 2AD

If ABC is an equilateral triangle such that AD perp BC, then AD^(2)=(3)/(2)DC^(2)(b)2DC^(2) (c) 3CD^(2)( d) 4DC^(2)

The base BC of Delta ABC is divided at D, so that BD=(1)/(2)DC. Prove that ar(Delta ABD)=(1)/(3)ar(Delta ABC)

In a ABC,/_ABC=135o. Prove that AC^(2)=AB^(2)+BC^(2)+4ar(ABC)

If AD is the median of Delta ABC, using vectors,prove that AB^(2)+AC^(2)=2(AD^(2)+CD^(2))