Advertisements
Advertisements
Question
Two angles of a quadrilateral are each of measure 75° and the other two angles are equal. What is the measure of these two angles? Name the possible figures so formed.
Advertisements
Solution
Let ABCD be a quadrilateral,
Where ∠A = ∠C = 75° and ∠B = ∠D = x ...[say]
Then, by the angle sum property of a quadrilateral, we have
∠A + ∠B + ∠C + ∠D = 360°
⇒ 75° + x + 75° + x = 360°
⇒ 2x = 360° – 150°
⇒ 2x = 210°
⇒ x = 105°
Thus, other two angles are 105° each.
Since, opposite angles are equal, therefore the quadrilateral is a parallelogram.
APPEARS IN
RELATED QUESTIONS
The measures of two adjacent angles of a parallelogram are in the ratio 3 : 2. Find the measure of each of the angles of the parallelogram.
The following figure GUNS is a parallelogram. Find x and y. (Lengths are in cm)


In the above figure both RISK and CLUE are parallelograms. Find the value of x.
Construct ☐ PQRS, such that l(PQ) = 3.5 cm, l(QR) = 5.6 cm, l(RS) = 3.5 cm, m∠Q = 110°, m∠R = 70°. If it is given that ☐ PQRS is a parallelogram, which of the given information is unnecessary?
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.
In parallelogram ABCD, X and Y are midpoints of opposite sides AB and DC respectively. Prove that:
(i) AX = YC
(ii) AX is parallel to YC
(iii) AXCY is a parallelogram.
ABCD is a parallelogram. Find the value of x, y and z.

A diagonal of a parallelogram bisects an angle. Will it also bisect the other angle? Give reason.
ABCD is a parallelogram. Points P and Q are taken on the sides AB and AD respectively and the parallelogram PRQA is formed. If ∠C = 45°, find ∠R.
The following figure RUNS is parallelogram. Find x and y. (Lengths are in cm)

