A shape is drawn on a centimetre grid. Write down the order of rotational symmetry of the shape.

Answer

The shape provided is an 'I' shape with an additional 1x1 block attached to the middle of its right side. To determine the order of rotational symmetry, we need to find how many times the shape looks identical as it is rotated a full 360 degrees around its center point. Let's analyze the shape: If we rotate the shape by 90 degrees clockwise, the 'I' part would be horizontal, and the 1x1 block would be on top or bottom, not matching the original orientation. If we rotate the shape by 180 degrees clockwise, the 'I' part would be upside down, and the 1x1 block would be on the left side of what was originally the right side. This orientation does not match the original shape. If we rotate the shape by 270 degrees clockwise, it will also not match the original. Only when the shape is rotated by 360 degrees (back to its original position) will it look exactly the same. Since the shape only looks identical to its original form once in a full 360-degree rotation (at 360 degrees or 0 degrees), its order of rotational symmetry is 1. Therefore, the order of rotational symmetry is 1.