A triangle, ABC, has angle measures of 60°, 60°, and 60° and three congruent (equal) sides. How would this triangle be classified?

A. Isosceles acute
B. Equilateral acute
C. Scalene acute
D. Equilateral obtuse



Answer :

To classify the triangle ABC, let's start by considering the given properties:

1. Angle Measures: The triangle has angles of [tex]\(60^\circ\)[/tex], [tex]\(60^\circ\)[/tex], and [tex]\(60^\circ\)[/tex]. Each angle is [tex]\(60^\circ\)[/tex], indicating that all angles in the triangle are equal.
2. Side Lengths: The triangle has three congruent (equal) sides.

Now, let’s go through the classification options:

### Types of Triangles by Side Length:
1. Equilateral Triangle: A triangle with all three sides of equal length.
2. Isosceles Triangle: A triangle with at least two sides of equal length.
3. Scalene Triangle: A triangle with all sides of different lengths.

Since ABC has three congruent sides, it is an Equilateral Triangle.

### Types of Triangles by Angle Measure:
1. Acute Triangle: A triangle where all three interior angles are less than [tex]\(90^\circ\)[/tex].
2. Obtuse Triangle: A triangle with one interior angle greater than [tex]\(90^\circ\)[/tex].
3. Right Triangle: A triangle with one interior angle equal to [tex]\(90^\circ\)[/tex].

Given that the angles of triangle ABC are [tex]\(60^\circ\)[/tex], [tex]\(60^\circ\)[/tex], and [tex]\(60^\circ\)[/tex], all angles are less than [tex]\(90^\circ\)[/tex]. Thus, it is an Acute Triangle.

Combining both classifications, the triangle ABC is an Equilateral Acute Triangle.

Therefore, the triangle ABC is correctly classified as:

Equilateral acute

So, the answer is:
- Equilateral acute