`vec(AB) = veca, vec(BC) = vecb` ltvrgt `therefore vec(AC) =vec(AB) + vec(BC) = veca + veca" "` (i)
` vec(AD) =2 vec(BC) = 2 vecb" "` (ii)
(because AD is parallel to BC and twice its length).
`vec(CD) = vec(AD) - vec(AC) = 2 vecb - ( veca + vecb)`
`= vecb - veca`
`" " vec(FA) = - vec(CD) = veca - vecb" "`(iii)
`vec(DE) = - vec(AB) = - veca" "`(iv)
`vec(EF ) =- vec(BC) = -vecb" "` (v)
` vec(AE) = vec(AD) + vec(DE) = 2vecb - veca" "` (vi)
`vec(CE) = vec(CD) + vec(DE) = vecb- veca - veca = vecb - 2 veca ` (vii)