It's April Fool's Day! I'm just glad that none of you played a prank on the teachers.
Did you know that in countries like Italy, France and Belgium, people tack paper fishes on each others' back as a trick and shout "April fish!" in their local languages?
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As for maths lesson today, we covered the topic on measuring angles where Miss Dee taught you how to use a protractor to measure angles accurately. But the learning doesn't just stop there! Miss Dee would like to take you on a journey to explore the history behind angles. Did you know that the protractor has been invented 4,000 years ago? I wonder who invented it ...
Learning Points
1) Protractor originates from the word "protract" which means to draw to scale.
2) There are four parts to the protractor : OBOI ( Origin, Base line, Outer scale, Inner scale)
3) How to use a protractor?
Step 1 : Align the base line of the protractor with line 1.
Step 2 : Slide the protractor along the base line til the vertex of the angle reaches the centre of the baseline .
Step 3 : Locate the origin ( where point zero is). From there, decide which scale to look at.
Step 4: Locate where line 2 is. Read the measurement off the scale.
Fun Online Games on Measuring Angles
( Click on the links below)
Measure the Angles by Mathsplayground
Kungfu Angles by BBC
This game requires you to estimate the angles in order for you to attack your opponent!
Below are some questions for you to ponder.
1) Besides the protractor and the full protractor, could you name me other instruments or ways to measure angles?
E.g The Full protractor (which I've shown it to you today)
2) What are the advantages and disadvantages of using the protractor?
( As what Anan has shared during class, the protractor can't measure angles up to 360 degrees. Could you think of more advantages or disadvantages?)
3) Remember I mention about the rule of 3-4-5 ? It's a rule which people follow to measure out right angles accurately. But, how does it works?
Answer:
A triangle with a right angle is formed when the slanted line of the triangle measures 5 units, horizontal line measures (4 units) or vertical line ( 3 units).
Regards,
Miss Dee
