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Secondary I • 1yr.

Hi! What distinguishes triangles from quadrilaterals other than their number of sides ?


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Explanations (1)

  • Explanation from Alloprof

    Explanation from Alloprof

    This Explanation was submitted by a member of the Alloprof team.

    Team Alloprof • 1yr.


    the answer to this question can be very elaborate.

    There are numerous similarities: they are polygons (closed chain), they have sides (segments of lines), angles, vertices (corners), etc. There are a lot of differences as well, besides the number of sides which is not the same:

    -A quadrilateral has 4 vertices. A triangle, 3.

    -A quadrilateral has 4 interior angles. A triangle, 3.

    -A quadrilateral has 4 exterior angles. A triangle, 3.

    -The sum of the measures of the interior angles of a quadrilateral is 360 °. That of a triangle is 180 °.

    -A quadrilateral has 2 diagonals. A triangle, 0.

    -A quadrilateral can be crossed. A triangle, no.

    -A quadrilateral can be convex or non-convex (concave). A triangle is always convex.

    -There are quadrilaterals that are equilateral but not equiangular (diamonds, and some quadrilaterals that are equiangular but not equilateral (rectangles). Equilateral triangles are always equiangular and vice versa.


    My pleasure!