Read the following statements:
An equilateral triangle is a polygon made up of three line segments out of which two line segments are equal to the third - one and all its angles are `60^(@)` each.
Define the terms used in this definition which you feel necessary. Are there any undefined terms in this ? Can you justify that all sides and all angles are equal in a equilateral triangle.

Explanation

To solve the problem step by step, we will define the necessary terms, identify any undefined terms, and justify why all sides and angles in an equilateral triangle are equal.

### Step 1: Define the Necessary Terms
1. **Polygon**: A polygon is a closed figure formed by a finite number of line segments connected end to end. Each line segment is called a side of the polygon.

2. **Line Segment**: A line segment is a part of a line that is bounded by two distinct endpoints. It has a definite length.

3. **Angle**: An angle is formed by two rays (or line segments) that share a common endpoint, called the vertex of the angle. Angles are measured in degrees.
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