Answer:
A. Line symmetry
C. Rotational symmetry ... 45°
Step-by-step explanation:
First of all, you need to have some idea what symmetry means.
A figure has line symmetry if it can be folded on a line and the halves of the figure lie on top of each other.
Here, any line through opposite vertices or through the midpoints of opposite sides is a line of symmetry. This figure has line symmetry.
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A figure has rotational symmetry if it can be rotated by some amount less than a full turn, and it lies on top of itself. The number of times you can do this in a full turn is the degree of the symmetry.
Here, the figure can be rotated 1/8 turn (360°/8 = 45°) and it will be indistinguishable from the original. It has rotational symmetry with angles of rotation that are multiples of 45°.
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Comment on symmetry of regular polygons
Any regular n-gon will have rotational symmetry of degree n, and symmetry about a line through its center and any vertex or side midpoint. (For odd n, such a line through a vertex goes through the midpoint of the opposite side.)
