a triangle that contains an obtuse interior angle

a triangle in which one of the angles is an obtuse angle

a triangle which contains one obtuse angle

a triangle that has an obtuse angle.

a triangle in which one angle is greater than 90

A triangle with at least one obtuse angle as described above.

One of the interior angles of an obtuse triangle is obtuse ( an obtuse angle is over 90 degrees).

A triangle having one angle over 90 degrees.

A triangle that contains one obtuse angle.

A triangle with exactly one obtuse angle (Lesson 2.6).