Quadrilateral / class 1-2-3 / knowledge Hub

 1- What is quadrilateral?

A closed figure that is bounded by four sides is called quadrilateral.

 A quadrilateral has four sides = AB , BC ,  CD , AD

A quadrilateral has four vertex = A , B , C , D

A quadrilateral has four angles = ∠BAD , ∠ABC ,

∠BCD , ∠ADC

    A quadrilateral has two diagonals = AC , BD

How many types of vertex in a quadrilateral.

Ans:- There are two types of vertex in a quadrilateral

1- adjacent vertex

2- Non-adjacent vertex

What are adjacent vertices?

Ans:- Two vertices which have a common side are called adjacent vertices. There are four pair of adjacent vertices in a quadrilateral.

Ex:- A and B , B and C , C and D , A and D

What are Non-adjacent vertices?

Ans:- Two vertices which have no common side are called Non-adjacent vertices. There are two pair of Non-adjacent vertices in a quadrilateral.

Ex:- A and C , B and D

What is diagonal?

Ans:- A line segment that is drawn between two non-adjacent vertices is called diagonal. There are two diagonals in aquadrilat

Ex:-

What are adjacent sides of a quadrilateral?

Ans:- Two sides which have a common vertex are called adjacent sides. There are four pairs of adjacent sides in a quadrilateral.

Ex:- AB and BC , BC and CD , CD and AD , AD and AB

What are opposite sides of a quadrilateral

Ans:- Two sides which have no common vertex are called opposite sides of a quadrilateral. There are two pairs of opposite sides in a quadrilateral.

Ex:- AB and CD , AD and BC

What are adjacent angles of a quadrilateral?

Ans:- Two angles of a quadrilateral which have a common arm are called adjacent angles of a quadrilateral. There are four pairs of adjacent angles in a quadrilateral

Ex:-

What are opposite angles of a quadrilateral?

Ans:- Two angles of a quadrilateral which have no common arm are called opposite angles of a quadrilateral. There are two pairs of opposite angles in a quadrilateral

Ex:-

2- What is the sum of all angles of a quadrilateral?

Ans:- The sum of all angles of a quadrilateral is 360°

Write the name of sides, vertex, angles and diagonals of given quadrilaterals

3- Fill in the blanks.

1- A quadrilateral has __________ angles.

2- A quadrilateral has __________ diagonals.

3- A quadrilateral has __________ sides.

4- A quadrilateral has __________ vertices.

4- In the quadrilateral ABCD, ∠A = 120° ,  ∠B = 100° and ∠C = 60° Find the measure of ∠D 

5- In the quadrilateral ABCD, ∠B = 100° ,  ∠C = 80° and ∠D = 70° Find the measure of ∠A 

6- In the quadrilateral ABCD, ∠A = 60° ,  ∠B = 130° and ∠C = 70° Find the measure of ∠D

 7- In the quadrilateral ABCD, ∠A = 110° ,  ∠C = 120° and ∠D = 70° Find the measure of ∠B

 8:- What are parallel lines ?

Ans:- Two lines are called parallel if they do not intersect at any point.

9:- What is parallelogram?

Ans:-  A quadrilateral whose opposite sides are parallel is called parallelogram.

Fill in the blanks 

1- A diagonal of a quadrilateral is a line segment that joins two ______ vertices of a quadrilateral.

2- The sum of the angles of a quadrilateral is __________.

3- A quadrilateral has __________ vertices, No three of which are _____.

The three angles of a quadrilateral are 76°, 54°, and 108° . Find the measure of fourth angle.

The three angles of a quadrilateral are 54°, 80°, and 116° . Find the measure of fourth angle.

The angles of a quadrilateral are in the ratio 3: 5 : 7 : 9. Find the measure of each of the angle.

 The angles of a quadrilateral are in the ratio 2 : 3 : 5 : 8. Find the angles.

A quadrilateral has three acute angles, each measuring 75° . find the measure of fourth angle.