Reference Book
POLYGON
Apolygonmaybedefinedasaplanefigureboundedbystraightlines.Itisa
planefigureboundedbymorethanfourstraightlinesandcontainingmore
thanfourangles.
Types of polygon
IfallthesidesandanglesofapolygonareequalitiscalledaRegularpolygon,
butifallthesidesandanglesare unequal,thenitiscalledanIrregularpolygon.- Regularpolygoncanbeinscribedin orcircumscribedaroundacircle
- Thepolygonsarenamedaccordingtothenumberoftheirsidesandangles.
PENTAGON
Pentagonisthatwhichhasfiveequalsidesandangles
Activity: Drawapentagonofagivenside(saya 35mmside) - Drawaline ABequalto35mm. BisectitatKand
- DrawKDperpendiculartoit.
- Cutof KM=AB.JoinBMandproduceitto NsothatMN=halfof AB.
- WithDascentreandradiusequaltoAB.draw
anarcEC. - WithAandBascentersandhavingsameradius
cutthepreviousarcat EandC. - JoinBC,CD,DEandEA.Then ABCDEisthe
required Pentagon.
HEXAGON
Hexagonisthatwhichhassixequalsidesandangles. Draw
ahexagonofgivenside(say35mmside) - Drawa Line ABequalto35mm.
- WithAandBascentersandradiusof 35mm,drawarcsintersectingat0.
- With 0 asthecentreandhaving35mmradius,drawthesegmentof acircle.
- With ABasradius,cutthesegmentatC, D, EandF.
- JoinBC,CD,DE,EFand FA.Then ABCDEFistherequired regular
hexagon.