Symétrie axiale - 6e

Les médiatrices

Exercice 1 : Construire la médiatrice du côté d'un triangle

Dans le triangle \(ABC\) suivant, tracer la médiatrice du segment \([AB]\).

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Exercice 2 : Reconnaître une médiatrice

Parmi les cas suivants, indiquer ceux dont la droite \((d)\) est la médiatrice du segment \([AB]\).

Exercice 3 : Reconnaître une médiatrice de segment

Parmi les figures suivantes, pour lesquelles la droite \((DC)\) est-elle la médiatrice du segment \([AB]\) ?

1.

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2.

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3.

{"init": {"range": [[-8.98171080877162, 1.0], [-8.53025656209119, 1.5406408837096053]], "scale": [30, 30]}, "label": [[[0.0, 0.0], "C", "above right", {}], [[-7.981710808771619, 0.5406408837096054], "A", "above left", {}], [[-2.7009694757776517, -7.530256562091188], "B", "below", {}], [[-5.341340142274635, -3.4948078391907913], "D", "below left", {}], [[-7.163604184613953, -1.8055906616463488], "5"], [[-4.523233518116968, -5.841039384546746], "5"]], "path": [[[[0.0, 0.0], [-7.981710808771619, 0.5406408837096054], [-2.7009694757776517, -7.530256562091188], [0.0, 0.0]], {"names": "CAB"}]], "line": [[[-7.981710808771619, 0.5406408837096054], [-5.341340142274635, -3.4948078391907913], {"subtype": "segment"}], [[-5.341340142274635, -3.4948078391907913], [-2.7009694757776517, -7.530256562091188], {"subtype": "segment"}], [[-1.4712169150466643, -3.509347630098873], [-1.2297525607309874, -4.020908931992315]], [[-2.7009694757776517, -7.530256562091188], [0.0, 0.0], {"subtype": "segment"}], [[-4.20391419669784, 0.08429369372825235], [-3.7777966120737787, 0.45634718998135304]], [[0.0, 0.0], [-7.981710808771619, 0.5406408837096054], {"subtype": "segment"}], [[-5.341340142274635, -3.4948078391907913], [0.0, 0.0], {"subtype": "segment"}]]}
4.

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Exercice 4 : Utiliser la propriété de la médiatrice

À l'aide de tes connaissances sur les médiatrices, détermine la ou lesquelles des égalités ci-dessous sont vraies pour cette figure :

1. \(RT = QS\)
2. \(QT = QR\)
3. \(TR = TQ\)
4. \(QT = ST\)

Exercice 5 : Construire la médiatrice du côté d'un triangle

Dans le triangle \(ABC\) suivant, tracer la médiatrice du segment \([AB]\).

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