The word locus (plural loci) is Latin for "place". In maths, a locus is a set of points whose location is determined by a specified condition (eg a set distance from a point is a circle around that point). To be able to answer loci questions effectively we need to do things like bisect an angle and draw a perpendicular bisector between two points. For tips see this website.
If you want to practise some loci questions, there is a homework task on MyMaths that you can have a go at.
We also look at
constructions in class, for example constructing an equilateral triangle.
Constructing involves drawing shapes, angles and lines accurately using a ruler
and a pair of compasses. Always use a
sharp pencil as accuracy is very important. For contruction methods look at this website.