Each angle of a rectangle is

If in a quadrilateral, two pairs of adjacent sides are equal, then it is called a

In the following figure the measure of \(\angle \)DAB is 
 

The angles of a quadrilateral are in the ratio 2 : 3 : 6 : 7. The largest angle of the quadrilateral is

Two consecutive angles of a parallelogram are in the ratio 1 : 3, then what will be the smaller angles?

In a parallelogram PQRS, if \(\angle \)QRS=2x, \(\angle \)PQS=4x, and \(\angle \)PSQ=4x, find the angles of the parallelogram.

If an angle of a parallelogram in two-third of its adjacent angle then find the measure of all the angles,

If angles of a quadrilateral are in ratio 1 : 2 : 3 : 4. Find the measure of all the angles of a quadrilateral.

Two parallel lines I and m are intersected by a transversal ' t'.Show that the quadrilateral formed by bisectors of interior angles is a rectangle.

The angle between the two altitudes of a parallelogram through the vertex of an obtuse angle is 50°. Find the angles of a parallelogram

Show that if the diagonals of a quadrilateral are equal and bisect each other at right angles, then it is a square.

ABCD is a trapezium in which AB II DC, BD is a diagonal and E is the mid-point of AD. A line is drawn through E parallel to AB intersecting BC at F (see figure). Show that F is the midpoint of B.

PQRS is a parallelogram and PL and RM are perpendiculars drawn from the vertices P and R of the parallelogram on diagonal SQ. Show that
(i) ΔPQL ≡ ΔRMS
(ii) PL = RM

In the given figure, PQRS is a parallelogram in which PT and QT are angle bisectors of ㄥP and ㄥQ respectively. Find the value of ㄥPTQ.

In a quadrilateral ABCD, the line segments bisecting  \(\angle \)C and \(\angle \) D meet at E. Prove that \(\angle \)A+\(\angle \)B=2\(\angle \)CED

ABCD is a parallelogram and line segments AX, CY bisects the angles A and C respectively. Show that AX II CY.

Show that the bisectors of angles of a parallelogram form a rectangle

In the given figure ABCD is a parallelogram and E is the mid-point of AD. A line through D, drawn parallel to EB, meets AB produced at F and BC at L Prove that
(i) AF = 2DC
(ii) DF = 2DL

There was four plants in Suraj's fields. Suraj named their bases of P, Q, R, S. He joined PQ, QR, RS and SP. His teacher told him that the quadrilateral PQRS was a parallelogram. He asked him to find the measure of all the angles of the parallelogram,
provided that the measure of anyone interior angle of PQRS. To obtain a technique and hence to solve the problem, he worked hard and spent much time.
(i) Obtain all the angles of the paralellogram PQRS if ㄥR=80°.
(ii) Which mathematical concept is used in the above problem?
(iii) Which value was depicted by Suraj on such a problem