the IB SL formula booklet Round to 3 s f if not otherwise specified 21 A garden includes a small lawn The lawn is enclosed by an arc AB of a circle with centre O and radius 6 m such that AOB 135 The straight border of the lawn is defined by chord AB The lawn is shown as the shaded region in the following diagram diagram not to scale 135 ing cal B a A footpath is to be laid around the curved side of the lawn Find the length of the