If you have the length of two of the sides and one other angle you can use the law of sines.
equilateral triangle
It is an acute triangle.
A right(-angled) triangle
Is called a scalene triangle.
A triangle having 3 congruent sides is an equilateral triangle
You can't without having incomplete units.
A scalene triangle is a triangle that has three unequal sides.
I believe that is called a Scalene triangle.
the same, "kwanzaa" - but note that is completely unknown in France and that nobody would understand the concept without having a look at Wikipedia.
A triangle with 3 equal sides is called an equilateral triangle.
An equilateral triangle can also be called a "regular" triangle
No, a regular isosceles triangle will not tessellate. In order for a shape to tessellate, it must be able to fit together with copies of itself without any gaps or overlaps. Regular isosceles triangles have angles of 90, 45, and 45 degrees, which do not allow for a repeating pattern that covers a plane without any spaces. Regular polygons that tessellate include equilateral triangles, squares, and hexagons.