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

Answer

The shape drawn on the centimetre grid is an isosceles triangle. An isosceles triangle has two sides of equal length and two equal base angles. Rotational symmetry refers to the number of times a shape can be rotated less than 360 degrees about its central point and look exactly the same as its original position. The 'order' of rotational symmetry is the count of how many times this happens. For a general triangle that is not equilateral, it can only ever be rotated 360 degrees to look the same. This means it only maps onto itself once in a full rotation. In the case of this specific isosceles triangle, if you try to rotate it, you will notice that it only looks the same as its original orientation after a full 360-degree rotation. It does not have any rotational symmetry for angles less than 360 degrees. Therefore, the order of rotational symmetry for this isosceles triangle is 1. All shapes have at least an order of 1 rotational symmetry (when rotated 360 degrees), but a shape is generally considered to have rotational symmetry if its order is greater than 1.