Definition :- A shape has a line of symmetry if, when folded over the line. 1 line of symmetry 2 lines of symmetry

Transcription

1 Symmetry Lines of Symmetry Definition :- A shpe hs line of symmetry if, when folded over the line the hlves of the shpe mtch up exctly. Some shpes hve more thn one line of symmetry : line of symmetry lines of symmetry 5 lines of symmetry Exercise (You will need ruler nd trcing pper).. Copy ech of the following netly, using trcing pper. Mrk with coloured pencil (or dotted line) ll the lines of symmetry. c d e f g h i j k l m n o Ntionl 4 Book N4- this is pge 36 Chpter 3 - Symmetry

2 . In this question, only hlf of ech figure is shown. Shown lso is line of symmetry (red dotted line). Copy these shpes into your jotter or onto trcing pper nd netly drw the other hlf. c d e f 3. Shown elow re ll the CAPITAL letters of the lphet. A B C D E F G H I J K L M N O P Q R S T U V W X Y Z List ALL the letters which hve exctly line of symmetry. List ALL the letters which hve exctly lines of symmetry. c Which letters hve NO lines of symmetry? d If the letters nd re drwn this wy, how mny lines of symmetry will ech one hve? Ntionl 4 Book N4- this is pge 37 Chpter 3 - Symmetry

3 4. The following shpes hve sloping line of symmetry. Trce ech one onto trcing pper (hrder to complete) or copy ech one onto centimetre squred pper or trce ech one crefully into your jotter cm squred) nd netly complete ech one. ( c 5. Do the sme here. This time, ech shpe hs lines of symmetry. c d e f Ntionl 4 Book N4- this is pge 38 Chpter 3 - Symmetry

4 Hlf Turn Symmetry Cn you see tht this S shpe hs no lines of symmetry? It hs different type of symmetry. It hs turn symmetry. If pin ws stuck in its centre point nd the shpe turned (or rotted) y 80 round the point, it would fit ck on itself. centre turn (80 ) Exercise. Which of the following shpes hve turn symmetry? (You might like to use piece of trcing pper to try them out if you re unsure). (Do NOT mrk the figures in the ook). c d e f g h i j k l m n o p Ntionl 4 Book N4- this is pge 39 Chpter 3 - Symmetry

5 . In Ex, you were sked to sy which letters of the lphet hd lines of symmetry. A B C... (Look ck three pges ). Which seven letters of the lphet hve turn symmetry? Of the seven letters which hve turn symmetry, only three do not hve line of symmetry. Which three? A shpe hs turn symmetry if it only tkes turn for the shpe to fit on itself. Some shpes hve different types of turn symmetry. 4 turn 3 turn 6 turn 4 turn symmetry 3 turn symmetry 6 turn symmetry (only needs 4 turn (90 ) (only needs 3 turn (0 ) (only needs 6 turn (60 ) to turn on itself). to turn on itself). to turn on itself). 3. Sy wht kind of turn symmetry ech of the following shpes hve. (, 3, 4, 5, 6, 8, etc... ) (Trcing pper my help). c d e f Ntionl 4 Book N4- this is pge 40 Chpter 3 - Symmetry

6 3. g h i j k l Rotting Given Shpe y Turn The red dot in this digrm hs to e the centre of symmetry when the shpe is rotted turn out it. 80 rottion clockwise 80 new position Exercise 3 (You will need ruler or stright edge nd cm squred pper).. Copy this rectngle onto centimetre squred pper. Rotte it y turn round the red dot.. Mke second copy of this rectngle. This time, rotte it y hlf turn round the new dot. Ntionl 4 Book N4- this is pge 4 Chpter 3 - Symmetry

7 3. Copy the letter T crefully onto centimetre squred pper. Rotte it y hlf turn round the dot. 4. Copy ech of the following shpes onto centimetre squred pper nd rotte ech y turn round the dot : c d e f g h i 5. Here is how to rotte complicted shpe round point, using mthemtics. Copy this shpe crefully onto squred pper. Look t corner. It is 7 oxes to the left of Point P. When rotted, it will end up 7 oxes to the right of P. (Show this). c Corner is 7 oxes left nd 6 oxes up from P. d It will end up 7 oxes right nd 6 oxes down from P. (Show this). Corner 3 is 4 oxes left nd 6 oxes up from P. 3 It will end up 4 oxes right nd 6 oxes down from P. (Show this) P Ntionl 4 Book N4- this is pge 4 Chpter 3 - Symmetry

8 5. e Corner 4 is... oxes left nd 4 oxes up from P. It will end up... oxes right nd 4 oxes.... from P. (Show this). f Corner 5 is... oxes left nd... oxes up from P. It will end up... oxes... nd... oxes... from P. (Show this). g Corner 6 is... oxes up from P. It will end up... oxes down from P. (Show this). h Join up your dots including P to find its new position. 6. Drw ech of the following nd use the Counting method to find ech new corner when the shpe is rotted y 80 round Point P. P P c d P P e f P P Ntionl 4 Book N4- this is pge 43 Chpter 3 - Symmetry

9 Order of Symmetry A shpe which hs A shpe which hs 3 A shpe which hs 4 A shpe which hs 0 turn symmetry is sid to hve order of symmetry of. turn symmetry is sid to hve order of symmetry of 3. turn symmetry is sid to hve order of symmetry of 4. turn symmetry is sid to hve order of symmetry of 0. Exercise 4. Stte the order of symmetry of shpe which hs turn symmetry of : 5 9 c 3 d 47.. Stte the order of symmetry nd the turn symmetry for ech of these shpes : squre pentgon c octgon d equilterl tringle e f g h 3. Copy ech of the following shpes onto centimetre squred pper. Complete ech shpe so tht it hs rottionl symmetry out O in the given order : c O O O order of symmetry of order of symmetry of 4 order of symmetry of 4 d e f O O O order of symmetry of order of symmetry of 4 order of symmetry of 4 g h i O O O order of symmetry of 4 order of symmetry of 4 order of symmetry of 4 Ntionl 4 Book N4- this is pge 44 Chpter 3 - Symmetry