QUADRILATERALS LECTURE 7)

12th MAY    LESSON 7

QUADRILATERALS

Guidelines for the Blog

·         The text in BLUE, is to be written in your register

·         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 SPECIAL PARALLELOGRAMS. 

Today's learning  outcomes

I will be able to:

Recall the properties of special parallelograms
identify a relation between special parallelograms
apply properties to solve questions

                            READ,VIEW AND UNDERSTAND

In the previous  class we have discussed about the properties of different quadrilaterals.

SO NOW, LET'S CHECK HOW MUCH YOU REMEMBER!  
                                 

                            NAME THE QUADRILATERAL IN EACH CASE

 CHECK YOUR ANSWERS!!

PARALLELOGRAM
RECTANGLE
RHOMBUS
SQUARE
TRAPEZIUM
ISOSCELES TRAPEZIUM

🏆🏆FOR THOSE WHO GOT ALL CORRECT!!


Today we will see how they are related to each other

watch the video

🟌🟌After watching this , you will be able to understand their linkage with each other.

1. In a kite, if all sides become equal it is known as RHOMBUS

So, we can say every rhombus is a kite.

2. In a trapezium, if both pairs of opposite sides become parallel, it is known as parallelogram.
So, every parallelogram is a trapezium.

3. In a parallelogram , if all sides become equal ,it is known as rhombus.
So, every rhombus is a parallelogram

4.In a parallelogram , if all angles  become equal ,it is known as rectangle
.So, every rectangle  is a parallelogram

6. Since a square has properties of rhombus as well as rectangle ,so a square is both rhombus and a rectangle.

7. But, we cant state it vice versa means
Every kite is not a rhombus

Every trapezium  is not a parallelogram and so on.

                                                          CLASS WORK

RELATIONSHIP BETWEEN DIFFERENT QUADRILATERALS

DRAW THE DIAGRAM NEATLY

⭐HERE TRAPEZOID REFERS TO A TRAPEZIUM


                                                  

                                            E X  3.4

1.  State whether True or False.

(a) All rectangles are squares

All squares are rectangles but all rectangles can’t be squares, so this statement is false.

(b) All rhombuses are parallelograms

True

 (e) All kites are rhombuses.

All rhombuses are kites but all kites can’t be rhombus.. 

FALSE

 (h) All squares are trapeziums

TRUE

3. Explain how a square is. 

(i) a quadrilateral (ii) a parallelogram (iii) a rhombus (iv) a rectangle 

ANS
(a) Having four sides makes it a quadrilateral

(b) Opposite sides are parallel so it is a parallelogram

(c) Diagonals bisect each at right angles and all sides are equal

 (d) Opposite sides are equal and angles are right angles so it is a rectangle.

5. Explain why a rectangle is a convex quadrilateral

Ans. Both diagonals lie in its interior, so it is a convex quadrilateral.

6. ABC is a right-angled triangle and O is the mid point of the side opposite to the right angle. Explain why O is equidistant from A, B and C. (The dotted lines are drawn additionally to help you).

Draw AD //BC and CD // AB

and ∠ B = 90º (given)

 we get a rectangle ABCD. Now AC and BD are diagonals of the rectangle.

          In a rectangle diagonals are equal and bisect each other.

          So, AC = BD

          AO = OC

          BO = OD

          And AO = OC = BO = OD

          So, it is clear that O is equidistant from A, B and C.


                  

EX 3.4

Q1 REMAINING PARTS

Q2,4

THIS BRINGS US TO THE END OF THIS CHAPTER

KEEP REVISING!!