show that the figure formed by joining the midpoints of sides of a rhombus successively is a rectangle
Answers
P,Q,R and S are the mid points of AB,BC, CD and AD respectively.
Proof:
In ΔABC, P and Q are mid points of AB and BC respectively.
∴ PQ|| AC and PQ = ½AC ..................(1) (Mid point theorem)
Similarly in ΔACD, R and S are mid points of sides CD and AD respectively.
∴ SR||AC and SR = ½AC ...............(2) (Mid point theorem)
From (1) and (2), we get
PQ||SR and PQ = SR
Hence, PQRS is parallelogram ( pair of opposite sides is parallel and equal)
Now, RS || AC and QR || BD.
Also, AC ⊥ BD (Given)
∴RS ⊥ QR.
Thus, PQRS is a rectangle.
Answer:
Given:- ABCD is a rhombus
E,F,G,H are the mid points of AB,BC,CD,DA
Formula used:- Line joining midpoints of 2 sides of triangle
Is parallel and half of 3rd side
Solution:-
BD is diagonal of rhombus
EH is the line joined by midpoints of triangle ABD,
∴EH is parallel and half of BD
GF is line joined by midpoints of side BC&BD of triangle BCD
∴GF is parallel and half BD
⇒ If HE is parallel to BD and BD is parallel to GF
∴ It gives HE is parallel to GF
⇒ If HE is half of BD and GF is also half of BD
∴ It gives HE is equal to GF
⇒ AC is another diagonal of rhombus
GH is the line joined by midpoints of triangle ADC,
∴GH is parallel to AC
∴GH is half of AC
FE is line joined by midpoints of side BC&AB of triangle ABC
∴FE is parallel to AC
∴ FE is half of AC
⇒ If GH is parallel to AC and AC is parallel to FE
∴ It gives GH is parallel to FE
⇒ If GH is half of AC and FE is also half of AC
∴ It gives GH is equal to FE
As diagonals of rhombus intersect at 90°
And AC is parallel to FE and GH
All angles of EFGH is 90°
All angles are 90° and opposite sides are equal and parallel
Conclusion:-
EFGH is a rectangle