JHS2 Mathematics · Term 3, Week 1

Shapes and Space

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Notes for this lesson are being prepared. The curriculum details below are complete and ready to use for your planning.

Curriculum details

Strand
Geometry and Measurement (Strand 3)
Sub-strand
Shapes and Space (3.1)
Content standard
B8.3.1.2 - Demonstrate the ability to perform geometric constructions of the angles (75˚, 105˚, 60˚, construct triangles and find locus of points under given conditions.
Indicator
B8.3.1.2.2 - Construct scalene triangles, isosceles triangles, equilateral triangles, obtuse-angled triangle, and acute-angled triangles in different orientations under given conditions.
Suggested placement
Term 3, Week 1 (Week 25 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, Common Core Programme (JHS1-JHS3), 2023, p. 127

Transcribed from the official NaCCA publication. Check this page against the source.

Exemplars (from the NaCCA curriculum)

E.g.1: Use a pair of compasses and a ruler to construct an equilateral triangle when a side is given and justify why it is an equilateral triangle (i.e. draw the line segment VJ = 6.2cm and use this radius at V and J respectively to strike arcs to intersect in N. Verify the measure of the size of the angle with a protractor)
Figure from the jhs2 mathematics curriculum, printed page 127
E.g.2 : Use a pair of compasses and a ruler to construct an equilateral triangle by using point A as a centre and constructing an arc to meet ⃗ AX in B, and then using the same radius to inscribe an arc (construct 60 0 angle) at point C and joining A to C and B to C.
Figure from the jhs2 mathematics curriculum, printed page 128
E.g.3: Use a pair of compasses and a ruler to perform geometric construction of an isosceles right-angled triangle when the base line is given.
Figure from the jhs2 mathematics curriculum, printed page 128
E.g.4: Use a pair of compasses and a ruler to perform geometric construction of an isosceles triangle when all the sides are given.
Figure from the jhs2 mathematics curriculum, printed page 129
E.g.5: Use a pair of compasses and a ruler to perform geometric construction of an isosceles triangle when the base angles and base side are known.
Figure from the jhs2 mathematics curriculum, printed page 130
E.g.6: Use a pair of compasses and a ruler to construct acute-angled triangles, obtuse-angled triangles and right-angled triangles when a side and two angles are given.
Figure from the jhs2 mathematics curriculum, printed page 130

            
        
          
              
Figure from the jhs2 mathematics curriculum, printed page 131
E.g.7: Use a pair of compasses i. Draw the line segment LM = 6cm. and a ruler to construct
ii. Taking a radius of 8cm, draw an arc of
triangles when all the sides are circle with centre L.
given.
iii. Draw another arc of circle with centre M and radius 7cm to intersect the first arc. Name the point of intersection N.
iv. Join the point L and N. Join the points M and N. hence triangle MNL is the required triangle.
Figure from the jhs2 mathematics curriculum, printed page 131

            
        
          
              
Figure from the jhs2 mathematics curriculum, printed page 132
E.g.8: Use a pair of compasses and a ruler to construct triangles when two sides and one angle are given In triangle ABC, ∠CAB = 450 , AC =3cm and AB=5cm
Figure from the jhs2 mathematics curriculum, printed page 132