To find a line of symmetry, look for two halves of the shape that are mirror images of each other. The right half of the shape is the mirror image of the left half. So, the vertical line that passes through the middle is a line of symmetry. A figure has rotational symmetry if it can be rotated by an angle between 0° and 360° so that the image coincides with the preimage. The angle of rotational symmetry is the smallest angle for which the figure can be rotated to coincide with itself.
<u>Radius</u>
A radius of a circle or sphere is any of the line segments from its center to its perimeter, and in more modern usage, it is also their length. The name comes from the Latin radius, meaning ray but also the spoke of a chariot wheel.
