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Nature d'un triangle - Définitions

Pour faire le point sur les façons de caractériser un triangle.

Caractériser un triangle selon la nature de ses angles

Les triangles acutangles

Un triangle start color #11accd, start text, a, c, u, t, a, n, g, l, e, end text, end color #11accd est un triangle dont les start color #11accd, start text, 3, space, a, n, g, l, e, s, end text, end color #11accd start color #11accd, start text, s, o, n, t, space, i, n, f, e, with, \', on top, r, i, e, u, r, s, space, a, with, \`, on top, space, end text, 90, degrees, end color #11accd, point Voici deux exemples de start color #11accd, start text, t, r, i, a, n, g, l, e, s, space, a, c, u, t, a, n, g, l, e, s, space, end text, end color #11accd:
A triangle with angle measures of 44 degrees, 68 degrees, and 68 degrees. The degree labels for all 3 angles are highlighted.
A triangle with angle measures of 60 degrees, 60 degrees, and 60 degrees. The degree labels for all 3 angles are highlighted.

Les triangles rectangles

Un triangle start color #7854ab, start text, r, e, c, t, a, n, g, l, e, end text, end color #7854ab est un triangle qui a start color #7854ab, start text, 1, space, a, n, g, l, e, space, d, e, space, end text, 90, degrees, end color #7854ab et 2 angles aigus. Voici deux exemples de start color #7854ab, start text, t, r, i, a, n, g, l, e, s, space, r, e, c, t, a, n, g, l, e, s, space, end text, end color #7854ab:
A triangle with angle measures of 90 degrees, 45 degrees, and 45 degrees. The 90 degrees angle label is highlighted.
A triangle with angle measures of 90 degrees, 54 degrees, and 36 degrees. The 90 degrees angle label is highlighted.

Les triangles obtusangles

Un triangle start color #1fab54, start text, o, b, t, u, s, a, n, g, l, e, end text, end color #1fab54 est un triangle qui a start color #1fab54, start text, u, n, space, a, n, g, l, e, space, end text, end color #1fab54 start color #1fab54, start text, s, u, p, e, with, \', on top, r, i, e, u, r, space, a, with, \`, on top, space, end text, 90, degrees, end color #1fab54 et 2 angles aigus. Voici deux exemples de start color #1fab54, start text, t, r, i, a, n, g, l, e, s, space, o, b, t, u, s, a, n, g, l, e, s, space, end text, end color #1fab54:
A triangle with angle measures of 118 degrees, 31 degrees, and 31 degrees. The 118 degrees angle label is highlighted.
A triangle with angle measures of 104 degrees, 42 degrees, and 34 degrees. The 104 degrees angle label is highlighted.
Exercice 1A
Le triangle P, Q, R est un triangle...
A triangle PQR with angle measures of 112 degrees, 36 degrees, and 32 degrees.
Choisissez une seule réponse :
Choisissez une seule réponse :

Caractériser un triangle selon les longueurs de ses côtés

Les triangles équilatéraux

Un triangle start color #11accd, start text, e, with, \', on top, q, u, i, l, a, t, e, with, \', on top, r, a, l, end text, end color #11accd est un triangle qui a start color #11accd, start text, t, r, o, i, s, space, c, o, with, \^, on top, t, e, with, \', on top, s, space, d, e, space, m, e, with, \^, on top, m, e, space, l, o, n, g, u, e, u, r, end text, end color #11accd. Voici deux exemples de triangles start color #11accd, start text, e, with, \', on top, q, u, i, l, a, t, e, with, \', on top, r, a, u, x, space, end text, end color #11accd:
A triangle with side lengths of 10, 10, and 10 units.
A triangle with side lengths of 2, 2, and 2 units.

Les triangles isocèles

Un triangle start color #7854ab, start text, i, s, o, c, e, with, \`, on top, l, e, end text, end color #7854ab est un triangle qui a start color #7854ab, start underline, start text, a, u, space, m, o, i, n, s, end text, end underline, end color #7854ab start color #7854ab, start text, d, e, u, x, space, c, o, with, \^, on top, t, e, with, \', on top, s, space, d, e, space, m, e, with, \^, on top, m, e, space, l, o, n, g, u, e, u, r, end text, end color #7854ab. Voici deux exemples de triangles start color #7854ab, start text, i, s, o, c, e, with, \`, on top, l, e, s, space, end text, end color #7854ab:
A triangle with side lengths of 5, 5, and 4 units.
A triangle with side lengths of 5, 7, and 5 units.

Les triangles quelconques (ou scalènes)

Un triangle start color #1fab54, start text, q, u, e, l, c, o, n, q, u, e, end text, end color #1fab54 est un triangle qui a start color #1fab54, start text, t, r, o, i, s, space, c, o, with, \^, on top, t, e, with, \', on top, s, space, d, e, space, l, o, n, g, u, e, u, r, s, space, d, i, f, f, e, with, \', on top, r, e, n, t, e, s, end text, end color #1fab54. Voici deux exemples de triangles start color #1fab54, start text, q, u, e, l, c, o, n, q, u, e, s, space, end text, end color #1fab54:
A triangle with side lengths of 6, 9, and 7 units.
A triangle with side lengths of 4, 7, and 5 units.
Exercice 2A
Le triangle P, Q, R est un triangle...
A triangle PQR. The angle at R has a box at its vertex connecting lines RP and RQ. Side RP is 5 units long, side RQ is 12 units long, and side PQ is 13 units long.
Choisissez toutes les réponses possibles :
Choisissez toutes les réponses possibles :