Transformations - 3e

Rotations

Exercice 1 : Tracer l'image d'un quadrilatère par une rotation (90°, 180° ou 270°)

Tracer l'image du quadrilatère \(ABCD\) par la rotation de \(270°\) dans le sens horaire de centre \(O\).

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Exercice 2 : Identifier un triangle de nature quelconque après rotation de 90 degrés.

Trouver la figure dans lesquelle \( A'B'C' \) est l'image du triangle \( ABC \) par la rotation de centre \( O \) suivant un angle de \( 90 °\) dans le sens des aiguilles d'une montre.

Exercice 3 : Image de point par rotation dans une grille de triangles équilatéraux

On s’intéresse à la figure ci-dessous composée de triangles équilatéraux :

Compléter les phrases suivantes :

J est l’image de K par la rotation de centre O d’angle ° dans le sens antihoraire.

C est l’image de E par la rotation de centre d’angle 240° dans le sens antihoraire.

J est l’image de par la rotation de centre I d’angle 180° dans le sens horaire.

est l’image de N par la rotation de centre J d’angle 120° dans le sens antihoraire.

Exercice 4 : Identifier un triangle de nature quelconque après rotation de 180 degrés.

Trouver la figure dans lesquelle \( A'B'C' \) est l'image du triangle \( ABC \) par la rotation de centre \( O \) suivant un angle de \( 180 °\) dans le sens inverse des aiguilles d'une montre.

Exercice 5 : Tracer l'image d'une figure par une rotation (90°, 180° ou 270°)

Tracer l'image de la figure suivante par la rotation de \(180 °\) dans le sens horaire de centre \(O\).

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