What are the properties of an equilateral triangle?

Equilateral triangles have, by definition, 3 equal sides. This means they also have 3 equal angles (i.e. they are equiangular) with each angle measuring 60 degrees. They have 3 lines of symmetry from each vertex to the midpoint of the opposite side. These lines are the medians, perpendicular bisectors, altitudes, and angle bisectors of the triangle. The point where these three lines intersect is the centroid, incenter, circumcenter, and orthocenter of the triangle. The area of an equilateral triangle is sqrt(3)/4*s where s is the side length of the triangle.