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?Prove' means what exactly?. A proof in mathematics is a process of logical stepsEach step makes a statement using facts that are recognised
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1. Proof of Pythagoras’s Theorem GCSE Higher
2. ‘Prove’ means what exactly? A proof in mathematics is a process of logical steps
Each step makes a statement using facts that are recognised & known to be true
In vast majority of cases, a proof involves some manipulation of algebra
3. Proof of Pythagoras’ Theorem Consider this square
It has side length c
It’s area is thus c2
4. Rotate the Square Surround it with another square
Label Triangles’ sides a & b
Now calculate area of large and small squares
SHADED is c2
5. Area Larger Square
= (a + b)2
= a2 + 2ab + b2
Area of EACH small Triangle = ˝ab
Area of 4 small triangles
= 2ab
6. Shaded Square’s area is…… = a2 + 2ab + b2 – 2ab
= a2 + b2
BUT Shaded Area is c2
SO
c2 =a2 + b2