An equilateral triangle is always an example of a/an:I. right triangleII. acute triangleIII. obtuse triangle A. II only B. III only C. I, II and III D. I only

An equilateral triangle is a triangle in which all three sides are equal. By definition, all the interior angles in an equilateral triangle are 60 degrees.

Let's analyze the options:

I. Right triangle: A right triangle is a triangle in which one of the angles is a right angle (90 degrees). An equilateral triangle does not have a 90 degree angle, so it is not a right triangle.

II. Acute triangle: An acute triangle is a triangle in which all of the angles are acute (less than 90 degrees). Since all the angles in an equilateral triangle are 60 degrees, it is an acute triangle.

III. Obtuse triangle: An obtuse triangle is a triangle in which one of the angles is obtuse (more than 90 degrees). An equilateral triangle does not have an obtuse angle, so it is not an obtuse triangle.

So, an equilateral triangle is always an example of an acute triangle only. Therefore, the answer is A. II only.