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Year 8 Mathematics Space AC9M8SP01

Locus and Geometric Constructions

A locus is the set of all points satisfying a given condition. Understanding loci connects to circle properties, perpendicular bisectors, and angle bisectors used in geometric constructions.

What You Need to Know

Key Concept Diagram

The locus of points equidistant from a fixed point is a circle

The locus of points equidistant from two points is the perpendicular bisector of the segment joining them

The locus of points equidistant from two lines is the angle bisector

Constructions use only a compass and straightedge without measurement

Key Vocabulary

Locus

The path or set of all points satisfying a given geometric condition

Perpendicular bisector

A line at right angles to a segment passing through its midpoint

Angle bisector

A ray that divides an angle into two equal parts

Equidistant

At equal distance from two or more reference points or lines

Knowledge Check

Select the correct answer for each question. Click "Check Answer" to see if you are right.

Question 1

What is the locus of all points exactly 4 cm from a fixed point P?

Question 2

What geometric object is the locus of points equidistant from points A and B?

Question 3

To bisect an angle using a compass, you create intersecting arcs to find a point on:

Key Concepts Summary