The figure shows a wooden cuboid that measures 139 m by 21 m by 21 m.
- Find the maximum number of 5-m cubes that can be cut from the wooden cuboid.
- Find the total surface area of the L-shaped block after cutting.
(a)
Number of cubes along the length
= 139 ÷ 5
= 27 r 4
Breath = Height
Number of cubes along the breadth or height
= 21 ÷ 5
= 4 r 1
Maximum number of 5 m cubes
= 27 x 4 x 4
= 432
(b)
Area of the 2 squares
= 2 x 21 x 21
= 882 m
2 Area of the top and bottom bases
= 2 x 139 x 21
= 5838 m
2 Area of 1 L-shaped side
= 139 x 1 + (21 - 1) x 4
= 139 + 80
= 219 m
2Area of 2 L-shaped sides
= 2 x 219
= 438 m
2 Total surface area
= 5838 + 882 + 438
= 7158 m
2 Answer(s): (a) 432; (b) 7158 m
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