Perimeter

Perimeter is simply the distance you would walk if you traced the whole outside edge of a shape and came back to where you started. You already know how to do this for straight-sided shapes. This lesson adds the piece that trips most students at O/L: the curved edge — the arc of a "slice" of a circle. Once you can measure an arc, you can find the length of a curved balcony railing, the bulbs needed along the curved top of a Vesak pandol, or the fencing around a wedge-shaped garden plot. It is a small idea that earns easy, reliable marks every single year.