In a quadrilateral ABCD, `angleA+angleD=90^(@)`. Prove that
`AC^(2)+BD^(2)=AD^(2)+BC^(2)`

In a quadrilateral ABCD angle B = angle D = 90 ^(@) Prove that : 2AC^(2) - BC^(2) = AB^(2) + AD^(2) +DC^(2)

In a quadrilateral ABCD,/_A+/_D=90^(@). Prove that AC^(2)+BD^(2)=AD^(2)+BC^(2)

In a quadrilateral ABCD, angleB=90^(@) and angleD=90^(@) . Prove that : " "2AC^(2)-AB^(2)=BC^(2)+CD^(2)+DA^(2)

In a quadrilateral ABCD, angleB=90^(@) and AD^(2)= AB^(2) + BC^(2)+CD^(2) prove that angleACD= 90^(@) .

In a quadrilateral ABCD, angleB=90^(@) and AD^(2)= AB^(2) + BC^(2)+CD^(2) prove that angleACD= 90^(@) .

In Figure 2,AD perp BC. Prove that AB^(2)+CD^(2)=BD^(2)+AC^(2)

In a quadrilateral ABCD, lfloorB=90^(@) . If AD^(2)=AB^(2)+BC^(2)+CD^(2) , prove that lfloorACD=90^(@) .

In a quadrilateral ABCD prove that AB^(2)+BC^(2)+CD^(2)+DA^(2)=AC^(2)+BD^(2)+4PQ^(2) where P and Q are middle points of diagonals AC and BD.

In a quadrilateral ABCD ,prove that AB^(2)+BC^(2)+CD^(2)+DA^(2)=AC^(2)+BD^(2)+4PQ^(2) where P and Q are middle points of diagonals AC and BD.

ABCD is a quadrilateral in which AD=BC and angleADB=angleCBA . Prove that: BD=AC