旋轉對稱 Rotational symmetry
旋轉對稱，形容當一個平面圖形以某點為中心旋轉一圈，與原有圖形重合兩次或以上。用於描述花的形狀。
Rotational symmetry, describe when a plane figure rotates around a central point of circle once and coincides with the original figure twice or more. Used to describe forms of flower petals.
