Enlargements:
• Objective: To enlarge shapes by negative
scale factors
Enlargements from a Given Point
X2
B/
A/
Image
A
D/
B
Object
D
C
To enlarge the rectangle
by scale factor x2 from
the point shown.
1. Draw the ray lines
through vertices.
C/
2. Mark off x2 distances
along each line.
3. Draw and label image.
Or Count
Squares
Centre of Enlargement
Negative Enlargements from a Given Point
B
A
Object
C
Centre of Enlargement
1. Draw ray lines
from each vertex
through C of E.
D/
D
Image
C/
B/
To enlarge the kite by
scale factor -1 from the
point shown.
A/
2. Mark off x1distances
along lines from C of E.
3. Draw and label image.
Image is Inverted
Or Count
Squares
-1
Negative Enlargements from a Given Point
B
A
Object
C
To enlarge the kite by
scale factor -2 from the
point shown.
Centre of Enlargement
1. Draw ray lines
from each vertex
through C of E.
D/
D
2. Mark off distances x2
along lines from C of E.
Image
C/
3. Draw and label image.
A/
Image is Inverted
B/
Or Count
Squares
-2
Finding the Centre of Enlargement
B
A
Object
The small kite has been
enlarged as shown. Find
the centre of
enlargement.
C
Centre of Enlargement
D/
D
Draw 2 ray lines through
corresponding vertices to
locate.
Image
C/
A/
B/
Find Centre
2