A line of symmetry is a line that divides a shape into two identical parts that are mirror images of each other.

An equilateral triangle has 3 lines of symmetry.

The degree of rotational symmetry for an equilateral triangle is 120 degrees.

A reflection transformation is a flip of a shape over a line, creating a mirror image.

To reflect a point over the y-axis, you change the sign of the x-coordinate while keeping the y-coordinate the same.

The new coordinates of point X after reflecting over the y-axis are (-3, -4).

A rotation transformation turns a shape around a fixed point, known as the center of rotation.