4.11 Symmetry and rotation

Mathematics

More geometry, data handling and probability

Educator section

Memorandum

5.

(a) symmetry line; symmetry axle

(b) 90 degrees

4

(c) (i) 6

(ii) 3

(iii) 2

Leaner section

Content

Activity: symmetry and rotation

5. SYMMETRY AND ROTATION

a) Refer back to the drawing at 1 b). What do we call the dotted line?

_____________________________________________________________________

b) Trace the following square and cut it out. Find the middle point by drawing in the diagonals. Attach your square to a piece of cardboard with a drawing pin. Make a dot in one corner of the square. Now draw the perimeter of the square on the cardboard using your pencil and a ruler.

• Rotate the dot clockwise (turn it right) to the following corner.

How many degrees has the square rotated? __________________________________

If you rotate the square 360 degrees, how many times have you turned it?

c) Do the same with the hexagon and triangle below.

i) How many times will the hexagon rotate in a full revolution? _____________________________________________________________________

ii) How many times does the triangle rotate in a full revolution? _____________________________________________________________________

iii) How many times does a rectangle rotate in a full revolution? _____________________________________________________________________