The answer is the option A, which is: A. Equilateral triangles.
The explanation for this answer is shown below:
By definition, a tetrahedron is a solid in three dimensions that has: six sides, four vertices and four triangular faces. These faces are equilateral triangles, which means that all the sides are equal and all the interior angles measure [tex] 60
[/tex] degrees.
The tetrahedron is also called "triangular pyramid".
Answer:equilateral triangles
Step-by-step explanation:
Apex
