A perimeter is a path that surrounds a twa-dimensional shape. The wird comes frae the Greek peri (aroond) and meter (measur). The term mey be uised either for the path or its length - it can be thoucht o as the length o the ootline o a shape. The perimeter o a circle or ellipse is cried its circumference.
Calculatin the perimeter haes considerable practical applications. The perimeter can be uised tae calculate the length o fence required tae surroond a yard or gairden. The perimeter o a wheel (its circumference) describes hou far it will roll in ane revolution. Similarly, the amoont o string woond aroond a spuil is relatit tae the spuil's perimeter.