Advertisements
Advertisements
Question
PQRS is a quadrilateral, PR and QS intersect each other at O. In which of the following case, PQRS is a parallelogram?
∠P =85°, ∠Q = 85°, ∠R = 95°
Advertisements
Solution
We have a quadrilateral named PQRS, with diagonals PR and QS intersecting at O.
∠P =85°, ∠Q = 85°, ∠R = 95°
By the angle sum property of a quadrilateral, we get:
∠P + ∠Q + ∠R + ∠S = 360
8585 + 95 + ∠S = 360
265 + ∠S = 360
∠S = 95
Clearly, ∠P ≠ ∠R
And ∠Q ≠ ∠S
Thus, we have PQRS a quadrilateral with opposite angles that are not equal.
Therefore,
PQRS is not a parallelogram.
APPEARS IN
RELATED QUESTIONS
The angles of quadrilateral are in the ratio 3: 5: 9: 13. Find all the angles of the quadrilateral.
Show that if the diagonals of a quadrilateral are equal and bisect each other at right angles, then it is a square.
In ΔABC and ΔDEF, AB = DE, AB || DE, BC = EF and BC || EF. Vertices A, B and C are joined to vertices D, E and F respectively (see the given figure). Show that
(i) Quadrilateral ABED is a parallelogram
(ii) Quadrilateral BEFC is a parallelogram
(iii) AD || CF and AD = CF
(iv) Quadrilateral ACFD is a parallelogram
(v) AC = DF
(vi) ΔABC ≅ ΔDEF.

In a parallelogram ABCD, ∠D = 135°, determine the measures of ∠A and ∠B
The following statement are true and false .
In any quadrilateral, if a pair of opposite sides is equal, it is a parallelogram.
The following statement are true and false .
If three sides of a quadrilateral are equal, it is a parallelogram .
In the given figure, ABCD and AEFG are two parallelograms. If ∠C = 58°, find ∠F.

Complete the following statement by means of one of those given in brackets against each:
If one angle of a parallelogram is a right angle, then it is necessarily a .................
PQRS is a quadrilateral, PR and QS intersect each other at O. In which of the following case, PQRS is a parallelogram?
OP = 6.5 cm, OQ = 6.5 cm, OR = 5.2 cm, OS = 5.2 cm
Diagonals of a quadrilateral ABCD bisect each other. If ∠A= 45°, then ∠B =
