Advertisements
Advertisements
Question
If three angles of a quadrilateral are 90° each, show that the given quadrilateral is a rectangle.
Advertisements
Solution
The given quadrilateral ABCD will be a rectangle, if its each angle is 90°
Since, the sum of interior angles of a quadrilateral is 360°.
∴∠A +∠B + ∠C + ∠D = 360°
⇒ 90° + 90° + 90° + ∠D = 360°
⇒ 270° + ∠D = 360°
⇒ ∠D = 360° – 270°
⇒ ∠D = 90°
Since, each angle of the quadrilateral is 90°. ∴The given quadrilateral is a rectangle.
APPEARS IN
RELATED QUESTIONS
In a quadrilateral, define of the following Adjacent sides .
In Fig. 16.19, ABCD is a quadrilateral.
How many pairs of adjacent angles are there?

In a quadrilateral ABCD, the angles A, B, C and D are in the ratio 1 : 2 : 4 : 5. Find the measure of each angle of the quadrilateral.
Two angles of a quadrilateral are 68° and 76°. If the other two angles are in the ratio 5 : 7; find the measure of each of them.
Use the information given in the following figure to find :
(i) x
(ii) ∠B and ∠C

The angles A, B, C and D of a trapezium ABCD are in the ratio 3: 4: 5: 6. Le. ∠A : ∠B : ∠C : ∠D = 3:4: 5 : 6. Find all the angles of the trapezium. Also, name the two sides of this trapezium which are parallel to each other. Give reason for your answer.
In parallelogram ABCD, its diagonals intersect at point O. If OA = 6 cm and OB = 7.5 cm, find the length of AC and BD.

Observe the figure below and find out their name.

Calculate the measure of each angle of a nonagon.
In quadrilateral ROPE, the pairs of adjacent angles are ______.
