This document discusses loci and their construction. It begins with an example of finding the locus of a dog on a 2 meter leash and recaps the definition of a locus as a set of points satisfying a particular condition. Several examples are then given of constructing different loci, including the locus of points equidistant from two other points, equidistant from a line, and equidistant from two lines. The objectives are to determine and draw loci based on given rules of movement.

1. Loci and Construction
With Mr.
Abdul Zahoor Sajid
Class: XI-C (Orange)
Objectives: Students will be able to
determine and draw the locus of an
object moving according to a rule

2. Recap of Previous Learning
A dog is chained to a post. The chain is 2
metres long. Where can the dog walk?
2 metres

3. A Locus/Loci are the set of points
satisfying a particular condition
2 metres
The dog is on a lead 2 metres long
Show where the dog is able to go

4. A Locus/Loci are the set of points
satisfying a particular condition
The dog is on a lead 2 metres long
Show where the dog is able to go

5. A Locus/Loci are the set of points
satisfying a particular condition
The dog is on a lead 2 metres long
Show where the dog is able to go

6. A Locus/Loci are the set of points
satisfying a particular condition
The dog is on a lead 2 metres long
Show where the dog is able to go

7. A Locus/Loci are the set of points
satisfying a particular condition
The dog is on a lead 2 metres long
Show where the dog is able to go

8. A Locus/Loci are the set of points
satisfying a particular condition
The dog is on a lead 2 metres long
Show where the dog is able to go

9. A Locus/Loci are the set of points
satisfying a particular condition
The dog is on a lead 2 metres long
Show where the dog is able to go

10. A Locus/Loci are the set of points
satisfying a particular condition
The dog is on a lead 2 metres long
Show where the dog is able to go

11. Join the dots with a…?

12. Locus of a moving point which is the exact same
distance from point P as it is from point Q
P
Q
Note: Every point on this new line is the
exact same distance from point P as it is
from point Q!

13. Locus of a moving point which is always at a distance
of 3cm from line AB
3cm
3cm
3cm
A
B

14. Locus of a moving point which is exact same distance
from line PQ as it is from line PR
Q
P
Crucial: You must not change the width of the
compasses at this stage!
R
Note: Every point on this new line is the
exact same distance from line PQ as it is
from line PR!

15. Show the set of points, inside the
triangle, equidistant from A and B
B
A
Show the set of points, inside the
triangle, equidistant from PQ and QR
C
P
R
Q