Symmetry

The shapes are the same, The sizes are the same, Corresponding sides are equal

After a rotation, the figure keeps the same shape and size. For the triangle rotated about vertex A, corresponding sides and angles remain equal. The number of sides does not change.

(0, 0)

The point (0, 0) remains (0, 0) under reflection in the x-axis, y-axis, and origin. So after all three reflections, it is still (0, 0).

AB equals AB prime, AC equals AC prime, Corresponding angles remain equal

In a rotation, the figure keeps the same shape and size. For a rotated triangle about vertex A, corresponding sides and angles stay equal.

The square has order 4 rotational symmetry, The equilateral triangle has order 3 rotational symmetry, A square fits onto itself four times in one complete rotation

A square matches itself 4 times in one complete rotation, so its order is 4. An equilateral triangle matches itself 3 times, so its order is 3.