Over the last week Grade 5B have been learning all about angles, or I guess I should really say they have been revising what they already knew about angles. They were very clever cookies when it came to identifying different types of angles and even knew how many degrees each angle should be.
We used lots of different things to model different angles, from string, to our bodies and even skipping ropes outside. We then spent time searching for angles out in the school yard. We found HEAPS!! We tried to focus on acute and obtuse angles as we tend to see right and straight angles everywhere!! See if you can identify the angles in the following slideshow.
After we had become familiar with angles again we looked at the following question:
HOW MANY TIMES ON A CLOCK ARE THERE WHERE THE HANDS MAKE A RIGHT ANGLE?
This question proved to be more difficult than we thought and there were a few steps and understandings that we needed before we could begin.
First we needed to know how many degrees there are in a circle. Well that’s easy I hear you all say, there are 360 degrees in a full turn
Then we needed to think about how many sections there are on a clock. We looked carefully and decided there were 12.
Now we needed to work out how many degrees there are in each section. To work this out we divided 12 into 360 to get an answer of 30 degrees. So when the time reads one o’clock the acute angle is 30 degrees. The reflex angle is 330 degrees.
We were then able to work out the two angles for 2:00, 4:00, 5:00, 7:00, 8:00, 10:00 and 11:00. Can you remember what they are? See if you can set this up in a table.
Now we want to explore the question about right angles! We know the two obvious answers are 3:00 and 9:00, but we’ve been told there are 20 others!
What have you learnt about angles?
How many of each angle did you see in the slideshow?
Were you able to discover all of the times that make a right angle?
What did you think of the page of angles games? Were any of them useful?