Not always, sometimes two obtuse triangles are similar and sometimes they are not similar.
Yes, they are.
Two equilateral triangles are always similar!
sometimes, the altitude of isosceles triangles resting on their base and equilateral triangles are angle bisectors
Sometimes triangular prisms have isosceles triangle bases. It is the most common, but they don't always have isosceles triangles.
Sometimes similar but it depends
No because isosceles triangles always have two equal sides
Nope sorry, a Rhombus will be split into 2 isosceles triangles and 1 equilateral triangle.
The two acute angles are always equal.