J's answer to Nancy woods's Primary 6 Maths Measurement Singapore question.
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You'll need to consider the dimensions of the paper (100cm by 60cm)
Every two triangles can be paired together to form a rectangle that is 10cm by 24cm.
You can cut the 10cm sides of the rectangles from the 60cm length of the paper.
Number of such rectangles that can be cut from this side = 60 cm ÷ 10 cm = 6
The 24cm sides can be cut from the 100cm breadth of the paper.
Number of such rectangles that can be cut from this side = 100cm ÷ 24cm = 4 R 4cm
So only 4 rectangles can be cut breadthwise. The remaining 4cm is not wide enough to cut more rectangles.
Total number of rectangles = 6 × 4 = 24
Since 2 triangles can be cut from each rectangle, total number of triangles = 24 × 2 = 48
Every two triangles can be paired together to form a rectangle that is 10cm by 24cm.
You can cut the 10cm sides of the rectangles from the 60cm length of the paper.
Number of such rectangles that can be cut from this side = 60 cm ÷ 10 cm = 6
The 24cm sides can be cut from the 100cm breadth of the paper.
Number of such rectangles that can be cut from this side = 100cm ÷ 24cm = 4 R 4cm
So only 4 rectangles can be cut breadthwise. The remaining 4cm is not wide enough to cut more rectangles.
Total number of rectangles = 6 × 4 = 24
Since 2 triangles can be cut from each rectangle, total number of triangles = 24 × 2 = 48
Date Posted:
2 years ago
If you do it the other way :
①Cut the 10cm sides from the 100cm length of the paper.
②Cut the 24cm sides from the 60cm breadth of the paper
Number of rectangles that can be cut lengthwise = 100cm ÷ 10cm = 10
Number of rectangles that can be cut breadthwise = 60cm ÷ 24cm = 2 R 12cm
Number of rectangles here = 10 × 2 = 20
Number of triangles here = 20 × 2 = 40
Now,
This 12cm space can fit more rectangles but they have to be oriented perpendicular (at right angles) to the other rectangles
Number of rectangles that fit this width = 1
(Since 12cm ÷ 10cm = 1 R 2cm)
Number of rectangles that fit along the 100cm length = 100cm ÷ 24cm = 4 R 4cm
Number of rectangles here = 4 × 1 = 4
Number of triangles here = 4 × 2 = 8
Total number of triangles = 40 + 8 = 48
It is still the same number, so the greatest number is still 48
①Cut the 10cm sides from the 100cm length of the paper.
②Cut the 24cm sides from the 60cm breadth of the paper
Number of rectangles that can be cut lengthwise = 100cm ÷ 10cm = 10
Number of rectangles that can be cut breadthwise = 60cm ÷ 24cm = 2 R 12cm
Number of rectangles here = 10 × 2 = 20
Number of triangles here = 20 × 2 = 40
Now,
This 12cm space can fit more rectangles but they have to be oriented perpendicular (at right angles) to the other rectangles
Number of rectangles that fit this width = 1
(Since 12cm ÷ 10cm = 1 R 2cm)
Number of rectangles that fit along the 100cm length = 100cm ÷ 24cm = 4 R 4cm
Number of rectangles here = 4 × 1 = 4
Number of triangles here = 4 × 2 = 8
Total number of triangles = 40 + 8 = 48
It is still the same number, so the greatest number is still 48
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