QUADRILATERALS (LECTURE 6)

11th MAY    LESSON 6

QUADRILATERALS

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·         The text in Red is to be viewed by clicking on it

·         The text in green is to be practiced for home work

·         Feel free to clarify your doubts by dropping a comment before going ahead in the lesson

IN THE PREVIOUS LESSONS YOU LEARNT ABOUT PROPERTIES OF PARALLELOGRAMS. 

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Today's learning  outcomes

I will be able to:

1.recall properties of parallelogram

2.comprehend and memorize about properties of special parallelograms

3.apply properties to solve questions.

                                      READ ,VIEW AND UNDERSTAND

WHAT IS A RHOMBUS?

LOOK AT THE FIGURE GIVEN BELOW

I   If you look closely at the figure , you will notice AB =AD. BC = CD

    You have already learnt that such quadrilaterals are known as KITE

   let's see if we make all sides of a KITE equal what do we get?

      

      This shape is known as a RHOMBUS

     Watch this

               

     DID U OBSERVE THE PROPERTIES OF A RHOMBUS?

      

     Infact, all properties of PARALLELOGRAM are present in RHOMBUS also?

      WHAT IS A RECTANGLE?

          Name the shape given below.

        You are right, it is a PARALLELOGRAM

               

       If we make all angles of parallelogram equal then how will this look like?

    Is it not looking like a rectangle? 

     WATCH THIS TO LEARN ABOUT THE PROPERTIES OF A RECTANGLE.

    

    NOW, IF WE TAKE A RECTANGLE AND MAKE ITS ALL SIDES EQUAL,WHAT WILL WE GET?

     YES, you get a square . So a square has all properties of rectangle and some extra ones also.

     Now,watch this video to learn about them.

    I HOPE YOU ALL HAVE GONE THRU THE VIDEOS. ITS TIME FOR WRITTEN WORK!!

                                                              CLASS WORK

                              

       I PROPERTIES OF A RHOMBUS

                    

Some of the important properties of the rhombus are as follows:

• All sides of the rhombus are equal.    (AB =BC=CD=AD)
• The opposite sides of a rhombus are parallel.( AB//CD  ,AD//BC)
• Opposite angles of a rhombus are equal. (∠A  =  ∠C  ,∠B  =  ∠D) 
• In a rhombus, diagonals bisecting each other at right angles.( AO= OC  ,BO = OD ,∠ AOD =90⁰)
• Diagonals bisect the angles of a rhombus.  
• The sum of two adjacent angles is equal to 180 degrees.
• The two diagonals of a rhombus form four right-angled triangles which are congruent to each other

    II  PROPERTIES OF A RECTANGLE

• The opposite sides are parallel and equal to each other
• Each interior angle is equal to 90 degrees
• The diagonals bisect each other
• Both the diagonals have the same length

    III  PROPERTIES OF A SQUARE

• All four interior angles are equal to 90°
• All four sides of the square are congruent or equal to each other
• The opposite sides of the square are parallel to each other
• The diagonals of the square bisect each other at 90°
• The two diagonals of the square are equal to each other
• The diagonals bisect the opposite angles means  BD bisects ∠ B  and  ∠ D     and AC bisects  ∠C and  ∠A

LOOK AT THE PROPERTIES AT A GLANCE

     

REVISE YOUR CW

WE END OUR CLASS HERE!

TAKE CARE!!