Crucigrama Properties of TrianglesVersión en línea A triangle is a closed shape that has three sides. por David Jiménez Hernández 1 if it has its three equal sides 2 if it has two of its equal sides. 3 it has its three unequal sides. 4 has an obtuse angle 5 has three acute angles 6 It is one that has an interior angle that is right, that is, it measures 90º. 7 It is a closed shape that has three sides. 8 9 10 8 4 2 6 10 7 9 5