Introduction to GEOMETRY Structure of Geometry Axiomatic Approach

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Introduction to GEOMETRY

Introduction to GEOMETRY

Structure of Geometry – Axiomatic Approach Body of Prepositions (or) Theorems Nature Riders (or)

Structure of Geometry – Axiomatic Approach Body of Prepositions (or) Theorems Nature Riders (or) Deductions

 • The Axioms forms from the 1 st and 2 nd stage of

• The Axioms forms from the 1 st and 2 nd stage of the Structure of Geometry, but Theorems forms from the 3 rd stage of the Structure of Geometry. • Using Undefined Terms, defined Terms and Axioms we can form some new relations. These Relations are called THEOREMS. • Axioms is a statement which has no question of proving it, but Theorem is the a statement which has to be proved using an Axiom. Body of Prepositions (or) Theorems Nature Riders (or) Deduction

Undefined and Defined Terms

Undefined and Defined Terms

AXIOMS

AXIOMS

1) Firstly we observe: - 2) Similarly, the Axioms: -

1) Firstly we observe: - 2) Similarly, the Axioms: -

But at the same time, we must take the following precautions when we formulate

But at the same time, we must take the following precautions when we formulate these Axioms.

 • The Direct Method of Proving: - • The Indirect Method of Proving:

• The Direct Method of Proving: - • The Indirect Method of Proving: -

 • Example: - “If x is odd, x 2 is odd. ” •

• Example: - “If x is odd, x 2 is odd. ” • This implication can be proved by Direct Method in the following way. Steps 1. x is an odd number 2. There exists a whole number k, such that x = 2 k + 1 3. 4. Reasons Hypothesis. Definition of odd number. x 2 = (2 k + 1)2 =4 k 2 + 4 k+ 1 =2(2 k 2 + 2 k)+1 =2 L + 1 L is a whole number. Squaring on both sides. x 2 is an odd number. By definition of odd number. When k is a whole number L=2 k 2 + 2 k also will be a whole number.

 • Example: - • Hypothesis: - • • Conclusion: Proof: - Therefore we

• Example: - • Hypothesis: - • • Conclusion: Proof: - Therefore we conclude that l and m must be parallel.

 • But to disprove a false statement it will suffice to give just

• But to disprove a false statement it will suffice to give just 1 example proving the falseness of the statement. This example is called the “Counter Example”. From this, we can establish that the statement is false. This method is called • When we observe these numbers, we see that all are not odd numbers. There is 1 even number in them. That number is ‘ 2’. So, the number ‘ 2’ is an example contradicting the given statement. This is called the counter example. With one example we conclude that the given statement is false.

India’s Contribution to GEOMETRY

India’s Contribution to GEOMETRY

 • The Pythagoras theorem was originally founded by the famous ‘Boudhayana’ in 600

• The Pythagoras theorem was originally founded by the famous ‘Boudhayana’ in 600 B. C.