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

Answer

The problem asks for the order of rotational symmetry of the given shape, which resembles a plus sign or a cross. Rotational symmetry is when a shape can be rotated less than 360 degrees about a central point and still look the same. The 'order' of rotational symmetry is the number of times a shape fits onto itself during a full 360-degree rotation. Let's analyze the given shape: 1. **Identify the center of rotation:** For this shape, the center of rotation is the central square where the four 'arms' of the plus sign meet. 2. **Rotate the shape and observe:** * **Original position:** The shape is oriented as a plus sign. * **Rotate 90 degrees clockwise (or counter-clockwise):** If you rotate the shape by 90 degrees, it will still look exactly the same as the original shape. The vertical arm will become the horizontal arm, and vice versa, but the overall appearance remains unchanged. * **Rotate 180 degrees:** After another 90-degree rotation (total 180 degrees from the start), the shape again looks identical to the original. * **Rotate 270 degrees:** After a third 90-degree rotation (total 270 degrees from the start), the shape still looks identical to the original. * **Rotate 360 degrees:** After a final 90-degree rotation (total 360 degrees from the start), the shape returns to its original position, as expected. 3. **Count the number of times it looks the same:** During a full 360-degree rotation, the shape looks identical to its original position at 0 degrees, 90 degrees, 180 degrees, and 270 degrees. Therefore, the shape fits onto itself 4 times during a 360-degree rotation. The order of rotational symmetry is 4.