CLASS:VII

Can you imagine some 4 sided figure in these pictures?????????????

But it is not easy to define quadrilateral as the union of segments

Suppose A,B,C,D are four points in a plane such that No three points are collinear.

. .

..

AB

CD Collinear means points which lies on a straight line.

Collinear means points which lies on a straight line.

If any two of the segments AB, BC, CD, DA have a common point, it is an end point only. That is,

A B

CD

1. No three points are collinear.

2. If any two of the segments AB, BC, CD, DA have a common point, it is an end point only.

If all above two conditions are satisfied then the union of segments AB, BC, CD and DA is called quadrilateral. It is denoted by -

ABCD

If we join the two triangles side ways the figure formed is quadrilateral

A B

CD

Sum of all the angles of the quadrilaterals is 360º

120º

60° 110°

How much is angle C ?

170°X

70° √

The sum of the measures of all angles of a triangle is _____.

1. 360° X

2. 180° √

3. 90° X

Different type of quadrilaterals are

1. Parallelogram

2. Rectangle.

3. Rhombus.

4. Square.

5. Trapezium.

6. Kite.

Parallelogram

Rectangle

Rhombus

Square

Trapezium

Kite

Answer the following questions.

1.Define quadrilateral.

2.Name the different types of quadrilaterals.

3.What is the sum of all the angles of quadrilateral?