theorems on quadrilaterals Archives – Mathemafia

Class 9 | Chapter 8 | Quadrilaterals | Example 8

Sunil Syal — Wed, 30 Sep 2020 07:31:01 +0000

Example 8: l, m and n are three parallel lines intersected by transversals p and q such that l, m and n cut off equal intercepts AB and BC on p (see Fig. 8.28). Show that l, m and n cut off equal intercepts DE and EF on q also.

Chapter 8 – Quadrilaterals

This playlist covers all the questions, concepts, theorems and examples of chapter 8 (Quadrilaterals) of class 9, NCERT textbook. Click a thumbnail to watch the tutorial.

Watch complete chapter on YouTube

Theorem 8.1, chapter 8 Class 9, Diagonal of a parallelogram divides it into two congruent triangles

Section 8.2, Class 9 – Angle sum property of quadrilateral | Sum of angles is 360 degrees

Theorem 8.2 chapter 8 class 9 | Prove that opposite sides of a parallelogram are of equal length

Theorem 8.3, ch 8 Class 9, Pair of opposite sides of quadrilateral is equal, it's a parallelogram

Equal Or Congruent ? Lines and Angles

Theorem 8.4, chapter 8 Class 9, How to prove that opposite angles of a parallelogram are congruent

Theorem 8.5, ch 8 Class 9, Pair of opposite angles of quadrilateral is equal, it's a parallelogram

Theorem 8.6, ch 8 Class 9, How to prove that the diagonals of a parallelogram bisect each other

Theorem 8.7, ch 8 Class 9, Diagonals of quadrilateral bisect each other, then it's a parallelogram

Class 9 | Chapter 8 | Example 1 Explanation | NCERT| Quadrilaterals – Each angle of rectangle is 90°

Example 2, Chapter 8, Class 9 – Diagonals of a square / rhombus are perpendicular to each other

Class 9 | Chapter 8 | Example 3 Explanation | NCERT| Quadrilaterals

Class 9 | Chapter 8 | Example 4 Explanation | NCERT| Quadrilaterals

Class 9 | Chapter 8 | Example 5 Explanation | NCERT Maths | Quadrilaterals

Theorem 8.8, Class 9, A pair of opp sides of quadrilateral is equal+parallel ⇒ it's a parallelogram

Question 1, Exercise 8.1, Ch 8, Class 9 | Parallelogram's diagonal are equal, then it's a rectangle

Question 2, Exercise 8.1, Ch 8, Class 9 | Diagonals of square are equal, bisect at right angles

Question 3, Exercise 8.1, Ch 8, Class 9 | Diagonal of parallelogram bisect the angles | Rhombus

Question 4, Ex 8.1, Ch 8, Class 9, Diagonal of rectangle bisects opposite angles, it is square

Question 5, Exercise 8.1, Ch 8, Class 9 Maths | Questions on Parallelograms and Congruent Triangles

Question 6, Exercise 8.1, Ch 8, Class 9 Maths | Questions on Parallelograms and Congruent Triangles

Question 7, Exercise 8.1, Ch 8, Class 9 Maths | Ques on Trapezium, Parallelogram, Congruent Triangle

Theorem 8.9 Chapter 8 Class 9 | MID POINT THEOREM | Proof in 2 different ways

Theorem 8.10 Chapter 8 Class 9 | CONVERSE OF MID POINT THEOREM | Proved by 3 different methods

Class 9 | Chapter 8 | Example 6 Explanation | NCERT Maths | Quadrilaterals

Class 9 | Chapter 8 | Example 7 Explanation | NCERT Maths | Quadrilaterals

Question 1 Exercise 8.2 Chapter 8 Class 9 | Proof | NCERT | Quadrilaterals

Question 2 Exercise 8.2 Chapter 8 Class 9 | Proof | NCERT | Quadrilaterals

Question 3 Exercise 8.2 Chapter 8 Class 9 | Proof | NCERT | Quadrilaterals

Question 4 Exercise 8.2 Chapter 8 Class 9 | Proof | NCERT | Quadrilaterals

Question 5 Exercise 8.2 Chapter 8 Class 9 | Proof | NCERT | Quadrilaterals

Question 6 Exercise 8.2 Chapter 8 Class 9 | Proof | NCERT | Quadrilaterals

The post Class 9 | Chapter 8 | Quadrilaterals | Example 8 appeared first on Mathemafia.

Class 9 | Chapter 8 | Quadrilaterals | Example 7

Sunil Syal — Wed, 30 Sep 2020 07:09:04 +0000

Example 7: In ∆ ABC, D, E and F are respectively the mid-points of sides AB, BC and CA (see Fig. 8.27). Show that ∆ ABC is divided into four congruent triangles by joining D, E and F.