Mathematics
Geometry
Volume
Educator section
Memorandum
Do you remember what the word parallel means? Write down the definition for it:
Invariable
1. A: Yes
B: Yes
2. C
1.
1.1 Obtuse
1.2 Right angle
1.3 Rotation
1.4 Acute
BRAIN-TEASER!
1. Acute
Obtuse
Straight
Right angle
2. Class discussion:
Leaner section
Content
Do you remember what the word parallel means? Write down the definition for it:
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Let's begin with some "puzzles"!
Look at the sketches below and answer the questions that follow:
1. Indicate whether EF and GH are parallel to one another in figure
A: __________________________________________________________________
B: __________________________________________________________________
2. Which is the extension of F: C or K?
Do you still remember?
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indicates a line: AB |
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indicates a line segment: EF |
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indicates a radius: CD |
Two lines that intersect form an angle.
The point where the lines meet is called the vertex.
We write this as: ÐABC
- Did you know?
The unit that we use for measuring angles is a degree. We measure
the size of the angle in degrees. We write an angle of 60 degrees as 60°.
You have to learn the different types of angles:
| Types of angles | |
| 1. The size of a rotation or full turn is 360° |
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| 2. A straight angle is a half turn and it is 180°. |
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| 3. A right angle is a quarter turn and it is 90°. |
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| 4. An acute angle is larger that 0°, but smaller than 90°. |
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| 5. An obtuse angle is larger than 90°, but smaller than 180°. |
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Activity: recognising and describing angles [lo 4.11]
1. How well do you know angles?
Work with a partner to see if the two of you can tell what the following angles are:
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Assessment
Learning Outcome 4: The learner will be able to use appropriate measuring units, instruments and formulae in a variety of contexts.
Assessment Standard 4.11: We know this when the learner recognises and describes angles in two-dimensional shapes, three-dimensional objects and the environment.