ABCD is a quadrilateral in which ab is equal to BC if P Q R S be the midpoint of Ab BC CD and BD respectively so that pqrs is a rhombus About the author Peyton
In △BAD, P and S are mid-points of AB and BD ⇒ PS∥AD and PS= 2 1 AD — ( 1 ) [ By BPT ] Similarly in △CAD, ⇒ OR∥AD and QR= 2 1 AD — ( 2 ) From ( 1 ) and ( 2 ), we get ⇒ PS∥QR and PS=QR= 2 1 AD —— ( 3 ) In △BDC, we get ⇒ SR∥BC and SR= 2 1 BC —– ( 4) And in △ABC PQ∥BC and PQ= 2 1 BC —— ( 5 ) ⇒ PQ∥SR, PQ=SR= 2 1 BC —- ( 6 ) [ From ( 4 ) and ( 5 ) ] ∴ □PQRS is a parallelogram. Now, AD=BC ∴ 2 1 AD= 2 1 BC ∴ PS=QR=PQ=SR [ From ( 3 ) and ( 6 ) ] ∴ □PQRS is a rhombus. Reply
In △BAD, P and S are mid-points of AB and BD
⇒ PS∥AD and PS=
2
1
AD — ( 1 ) [ By BPT ]
Similarly in △CAD,
⇒ OR∥AD and QR=
2
1
AD — ( 2 )
From ( 1 ) and ( 2 ), we get
⇒ PS∥QR and PS=QR=
2
1
AD —— ( 3 )
In △BDC, we get
⇒ SR∥BC and SR=
2
1
BC —– ( 4)
And in △ABC
PQ∥BC and PQ=
2
1
BC —— ( 5 )
⇒ PQ∥SR, PQ=SR=
2
1
BC —- ( 6 ) [ From ( 4 ) and ( 5 ) ]
∴ □PQRS is a parallelogram.
Now, AD=BC
∴
2
1
AD=
2
1
BC
∴ PS=QR=PQ=SR [ From ( 3 ) and ( 6 ) ]
∴ □PQRS is a rhombus.