Well, it has three sides and three angles and must be completely enclosed.
Three straight lines meeting pair-wise at three vertices.
hexagons and a triangle
A scalene triangle makes it scalene because all sides have different length.
It makes a trapezoid.
because its a triangle
A trapezoid and a triangle make a paralellogram.
The pyramids are not triangle so the question makes no sense.
It is an isosceles triangle
A right(-angled) triangle
A right triangle is one that has a right angle.
When it has 2 equal sides it is an isosceles triangle
An obtuse triangle has one angle greater than 90 degrees.
texas iron triangle