Fundamentals of Geometry (Leaving Cert Mathematics): Flashcards

📚Flashcards
Formal Proofs of Theorems
Sign up to keep revising.Create a free account to study more flashcards and track your progress.

Practise the cards

15 cards from this deck

Show

Formal proofs definition

Structured methods proving geometric results using logic

Developer of formal proofs (300 BC)

Euclid

Axiom definition

Statement accepted as true without needing proof

Theorem definition

Statement proven true using axioms and logical reasoning

Four components of every formal proof

Given, To Prove, Construction, Proof

Theorem 1: Angle opposite longer side is...

Greater than angle opposite shorter side

Theorem 2: Triangle inequality rule

Sum of any two sides >> third side

Theorem 3: Three parallel lines on transversals

Equal segments on one = equal on any other

Theorem 4: Line parallel to triangle side divides...

Other two sides in same proportion

Theorem 5: Similar triangles have...

Proportional corresponding sides

Theorem 6: Base ×\times height in triangle

Product constant regardless of which side is base

Theorem 9: Tangent line to circle is...

Perpendicular to radius at point of contact

Theorem 10: Line from centre \perp to chord...

Bisects that chord

Proof by contradiction method

Assume opposite, show it leads to impossible situation

Three triangle congruence rules

SSS, SAS, RHS

Explore Leaving Cert Mathematics Revision Notes by Topics

Explore Leaving Cert Mathematics Model Answers by Topics

Explore Leaving Cert Mathematics Quizzes by Topics

Explore Leaving Cert Mathematics Exam Questions by Topics

Join 100,000+ Leaving Cert students studying Flashcards with us.

Select your subjects, and get access to A+ resources today.