Advertisements
Advertisements
Question
Two adjacent angles of a parallelogram have equal measure. Find the measure of each of the angles of the parallelogram.
Advertisements
Solution

Let ABCD be a parallelogram, in which, let m∠A = m∠B = x
Since sum of two adjacent angles is 180°
∠A + ∠B = 180º
x + x = 180°
2x = 180°
x = 90º
∠C = ∠A = 90º (Opposite angles)
∠D = ∠B = 90º (Opposite angles)
Thus, each angle of the parallelogram measures 90º.
APPEARS IN
RELATED QUESTIONS
Given a parallelogram ABCD. Complete each statement along with the definition or property used.

- AD = ______
- ∠DCB = ______
- OC = ______
- m∠DAB + m∠CDA = ______
Consider the given parallelogram. Find the values of the unknowns x, y, z.

Can a quadrilateral ABCD be a parallelogram if AB = DC = 8 cm, AD = 4 cm and BC = 4.4 cm?
The adjacent figure HOPE is a parallelogram. Find the angle measures x, y and z. State the properties you use to find them.

In the following diagram, the bisectors of interior angles of the parallelogram PQRS enclose a quadrilateral ABCD.

Show that:
(i) ∠PSB + ∠SPB = 90°
(ii) ∠PBS = 90°
(iii) ∠ABC = 90°
(iv) ∠ADC = 90°
(v) ∠A = 90°
(vi) ABCD is a rectangle
Thus, the bisectors of the angles of a parallelogram enclose a rectangle.
The adjacent sides of a parallelogram are 5 cm and 9 cm. Its perimeter is ______.
If opposite angles of a quadrilateral are equal, it must be a parallelogram.
In parallelogram PQRS, O is the mid point of SQ. Find ∠S, ∠R, PQ, QR and diagonal PR.

The angle between the two altitudes of a parallelogram through the vertex of an obtuse angle of the parallelogram is 45°. Find the angles of the parallelogram.
The following figure RUNS is parallelogram. Find x and y. (Lengths are in cm)

