Question 6 • CA-Common Core Geometry DVHS Sem. 1
A regular polygon has 180° rotational symmetry when a half-turn maps it onto itself, which happens for regular polygons with an even number of sides. The regular octagon, regular hexagon, and square have 8, 6, and 4 sides, respectively, so they qualify. The regular pentagon and right isosceles triangle do not match themselves after a 180° turn.
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