B5 Mathematics · Term 3, Week 7
Measurement - Angles
Lesson notes
Learning Objectives
Indicator: B5.3.3.3.2
By the end of the lesson, learners can:
- Measure a given angle accurately using a protractor, reading the correct scale.
- Classify measured angles as right (exactly 90°), acute (less than 90°), obtuse (between 90° and 180°), or reflex (between 180° and 360°).
- Sort a set of measured angles into groups by type, justifying each classification.
- Draw angles of given sizes (30°, 45°, 60°, 75°, 90°, 120°, 150°, 270°) using a protractor.
- Identify whether an angle is acute or obtuse by estimating its size before measuring, then confirm with the protractor.
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Sign in with phone numberCurriculum details
- Strand
- Geometry and Measurement (Strand 3)
- Sub-strand
- Measurement - Angles (3.3)
- Content standard
- B5.3.3.3 - Demonstrate an understanding of angles
- Indicator
- B5.3.3.3.2 - Measure given angles with a protractor and classify them according to their measured sizes - right, acute, obtuse and reflex
- Suggested placement
-
Term 3, Week 7
(Week 31 of the year)
Our suggestion, laid out in curriculum order across three terms of twelve weeks. NaCCA does not fix the week, so follow your school's scheme of learning.
- Curriculum reference
-
Mathematics Curriculum for Primary Schools (Basic 4-6), 2019, p. 104
Transcribed from the official NaCCA publication. Check this page against the source.
Exemplars (from the NaCCA curriculum)
E.g. 1 Review with learners how to use the protractor to measure angles E.g. 2 Give learners photocopied worksheets with protractor in position measuring angles; ask them to read the angles or place their protractors on it and read it E.g. 4 Give learners photocopied worksheets with several angles to measure and sort into those which are - right, acute obtuse angles. E.g. 5 Ask learners to draw various angles such as 30 o , 45 o ,60 o , 75 o , 90 o , 120 o , 150 o ,270 o , etc.
