A pair of triangles can form a 4 sided quadrilateral
You could draw four different triangles in a 4-sided polygon, but two are enough to define the polygon.
Equilateral triangles have 3 sides all of the same lengths and the three angles are equal (60°). Isoceles triangles have two sides of equal length with both of those side angles being equal while the other is different. Scalane triangles have all sides of different lengths and different angles. Right angled triangles have one angle of 90° and the other two will total 90°.
A three-sided shape is called a triangle. There are three types of triangles: equilateral triangles, iscosceles triangles, and scalene triangles. Equilateral triangles have all equal sides and angles; iscosceles triangles have two congruent legs and a base, and scalene triangles do not have any equal sides or angles.
scalene triangles
Those would be SIMILAR triangles.
Five. They are:Tetrahedron (4 triangles)Cube (6 squares)Octahedron (8 triangles)Dodecahedron (12 pentagons)Icosahedron (20 triangles).
They are 4 triangles and one square. What they might make when assembled together depends on their sizes and on the shapes of the triangles.
4 right triangles
you can make 76 different triangles on a 3x3 grid
Similar triangles
The set of all triangles, probably.
One way is they both are triangles and have 3 sides.
a square pyramid has 4 triangles
A 6 sided hexagon has 4 triangles
3 triangles make up a hexagon.
Isosceles triangles are triangles in which two of the three sides have different lengths.