An equilateral triangle is a type of triangle that has three equal sides and three equal angles. The word "equilateral" comes from the Latin roots "equi," which means "equal," and "lateral," which means "side." This means that all three sides of an equilateral triangle have the same length, and all three angles are equal, each measuring 60 degrees.

In an equilateral triangle, the properties are as follows:

• All three sides are equal in length.
• All three angles are equal and measure 60 degrees.
• The sum of the interior angles of an equilateral triangle is always 180 degrees.
• The altitude, median, and angle bisectors of an equilateral triangle are all the same line.

Visually, an equilateral triangle looks like an isosceles triangle with all sides and angles being congruent. It is a fundamental shape in geometry and is commonly found in various mathematical and real-world applications.