Angle construction-upper primary mathematics
Constructing Angles of 60º, 120º, 30º, 150, 90º and 450
How to construct an angle of 600.
(i) Draw a line and select point A.
(ii) With a compass placed at A make an arc BC.
(iii) Without adjusting the compass, place the compass at B and make an arc A-D to intersect with arc BC at E
(iv) Connect A to E and angle BAE = 600
How to construct angle 300
By bisecting angle 600.
(i) Construct angle 600 as in (a) and bisect it as follows
(ii) Place a compass at E and make an arc FG
(iii) Without adjusting the size of compass; place it at B and make an arc HI to intersect at J
(iv) Draw a line from A through J
(v) Angle JAB = 300
How to prepare angle 15
By bisecting angle 300
(ii) Place a compass at K and make an arc NO
(iii) Without adjusting the size of compass; place it at B and make an arc LM to intersect at P
(iv) Draw a line from A through P
(v) Angle JAB = 150
How to prepare 1200
1200 = 1800 – 600
How to construct angle 900
- Draw a straight line and mark points AB
- Place a compass at point A and make arcs 1-2 and 3- 4
- Without adjusting the compass, place it at point B and make arcs 5-6 and 7- 8
- Draw through the intersection of arcs at C and D to meet line AB at E
- Angle CEB = 900.
Or
- Draw a line and mark point A
- Using a compass mark points B and C equidistant from A
- Place a compass at point B and make an arc 1-2.
- Without adjusting the length of a compass, place it at C and make an arc 3-4 to intersect with arc 1-2 at D.
- Draw a line at A through D
- Angle DAC = 900.
How to prepare 450
By bisecting angle 900
- Prepare an angle 900
- Place a compass at E and mark points F and G.
- Place a compass at F and make an arc 9-10.
- Without adjusting the compass place it at G and make an arc 11- 12 to intersect with arc 9 – 10 at H.
- Connect E to H
- Angle HEG = 450
How to bisect a line AB
- Place a protractor at A and make arcs 1-2 and 3-4.
- Without adjusting the size of the compass place it at B and arc 5-6 to intersect arc 1-2 at C; then make arc 7-8 to intersect arc 3-4 at D.
- Draw a perpendicular bisector through C and D.
To try out some numbers by down load PDF below
Angle construction- upper primary
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hello I am Jeremie, I am a teacher of Mathematics in O level here in Rwanda. I have seen that this website can help in my teaching. I have seen that Mathematics in O level does not have answers as you did it in physics. please if possible you can upload it.
soon
Why can’t you upload
Full o level mathematics Notes
soon
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