Show that the quadrilateral formed by joining the midpoints of the pairs of adjacent sides of rhombus is a rectangle
Answers
Question :-
Show that the quadrilateral formed by joining the midpoints of the pairs of adjacent sides of rhombus is a rectangle .
Answer :-
Consider △ ABC
We know that P and Q are the mid points of AB and BC
By using the midpoint theorem
We know that PQ || AC and PQ = ½
AC Consider △ ADC
We know that RS || AC and RS = ½
AC It can be written as PQ || RS and PR = RS = ½ AC ……. (1) Consider △ BAD
We know that P and S are the mid points of AB and AD
Based on the midpoint theorem
We know that PS || BD and PS = ½
DB Consider △ BCD
We know that RQ || BD and RQ = ½
DB It can be written as PS || RQ and PS = RQ = ½ DB …….
(2) By considering equations (1) and (2)
The diagonals intersects at right angles in a rhombus
So we get ∠ EQF = 90o
We know that RQ || DB
So we get RE || FO
In the same way SR || AC
So we get FR || OE
So we know that OERF is a parallelogram.
We know that the opposite angles are equal in a parallelogram.
So we get ∠ FRE = ∠ EOF = 90o
So we know that PQRS is a parallelogram having ∠ R = 90o
⏩ Therefore, it is proved that the quadrilateral formed by joining the midpoints of the pairs of adjacent sides of a rhombus is a rectangle.⏭️
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@brainlyqueen23
Let ABCD be the rectangle and P,Q,R,S be the midpoints of AB,BC,CD,DA respectively.
Join AC, a diagonal of the rectangle.
In ΔABC, we have:
PQ∣∣AC and PQ=21AC [By midpoint theorem]
Again, in ΔDAC, the points S and R are the mid points of AD and DC, respectively.
SR∣∣AC and SR=21AC [By midpoint theorem]
Now, PQ∣∣AC and SR∣∣AC and PQ∣∣SR
Also, PQ=SR [Each equal to 21AC] . . . . . . . (i)
So, PQRS is a parallelogram.
Now, in ΔSAP and ΔQBP, we have:
AS=BQ,∠A=∠B=90∘andAP=BP
i.e.,ΔSAP∼ΔQBP
PS=PQ . . . . . . . . . (ii)
Similarly, ΔSDR∼ΔQCR
SR=RQ . . . . . . . . (iii)
From (i), (ii) and (iii), we have:
PQ=PS=SR=RQ
Hence, PQRS is a rhombus.