This page explores the Thales theorem and its application in determining parallel lines. The content provides detailed examples of how to verify parallel lines using proportional relationships.

Definition: Thales theorem states that if points A, M, B and A, N, C are aligned in the same order and certain proportional relationships exist, then lines (MN) and (BC) are parallel.

Example: Using measurements 4.5, 7.5, and 6 units to verify parallel lines through proportional relationships.

Highlight: The theorem requires careful attention to point alignment and ratio comparisons.

Vocabulary: "Triangle emboîté" - nested triangles, where one triangle is contained within another with parallel corresponding sides.

This page introduces the fundamental concepts of the Pythagorean theorem and its applications in right triangles. The content focuses on practical calculations and verification of right angles in triangles.

Definition: In a right triangle, the square of the hypotenuse equals the sum of squares of the other two sides $a² + b² = c²$.

Example: A triangle with sides 4, 5, and 6 units is analyzed to determine if it's right-angled by checking if 16 + 25 = 36.

Highlight: The verification process involves squaring each side length and comparing the sum of squares of two sides with the square of the longest side.

Vocabulary: Hypotenuse - the longest side of a right triangle, opposite to the right angle.