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PolygonsPolygonsStage 5Stage 5Year 9Year 9

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Definition of a PolygonDefinition of a PolygonA closedclosed plane figure with

threethree or more straightstraight sides.

ClosedClosed OpenOpen

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Regular Regular Polygons?Polygons?

33 44 55

66 77 88

99 1100

1122

NumberNumberOf SidesOf Sides

Click On/OffClick On/Off

TriangleTriangleSquareSquarePentagonPentagonHexagonHexagonHeptagonHeptagonOctagonOctagonNonagonNonagonDecagonDecagonDodecagonDodecagon

They have They have allall anglesangles

and and all all sidessides

equal in equal in size.size.

Polygon Golf

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Convex and Non-ConvexConvex and Non-Convex(Concave)(Concave)

All internalinternal angles less thanless than

180180oo

Some internalinternal angles greater greater

thanthan 180180oo

All diagonalsdiagonals lie insideinside the polygon .

Some diagonalsdiagonals lie outsideoutside the

polygon.

OutsidOutsidee

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ReflexAngle