SENIOR ONE Reflection Lesson one 025.ppt

REFLECTION
SYMMETRY

2. © T Madas

3. Competency:
•The learner reflects shapes in a range of
contexts and identify lines of symmetry.

4. LEARNING OUTCOMES
•The learner should be able to:
a) identify lines of symmetry for di erent
ff
figures.
b) reflect shapes and objects.
c) apply reflection in the Cartesian plane.

5. KEY WORDS
•LINE OF SYMMETRY
•REFLECTION
•MIRROR LINE
•MEDIATOR
•OBJECT
•IMAGE
•INVARIANT POINTS
•CONGRUENCE
•CARTESIAN PLANE

6. Identify Lines of
Symmetry for Different
Figures

7. ACTIVITY
•Take the rectangular sheet of paper.
•Fold it lengthwise (along its longer side)
so that one half fits exactly over the other
half.
•Press and crease the edges firmly.
•Open the paper — the fold line you see is the
first line of symmetry.

8. ACTIVITY
•Now, fold the same rectangular sheet
widthwise (along its shorter side)
so that one half overlaps perfectly
with the other.
•Press and crease the edges again.
•Open the paper

9. OBSERVATIONS
•What have you observed on your paper

10. Definition
•Line of Symmetry is defined as the axis or
imaginary line that passes through the
center of the shape or object and divides it
into identical halves. In other words a Line of
Symmetry divides a figure into two parts
such that when the figure is folded along
the line, the two parts of the figure
coincide(match).The line of symmetry is also
called the mirror line or axis of symmetry.

12. © T Madas
Reflection Practice