Problem 4 · 2010 Math Kangaroo
Easy
Geometry & Measurement
areaspatial-reasoning
The object pictured is made up of four equally sized cubes. Each cube has a surface area of 24 cm². What is the surface area of the object pictured?
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Answer: B — 64 cm²
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Hint 1 of 2
First find the side of one cube from its surface area.
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Hint 2 of 2
Count only the faces on the outside of the joined block; hidden touching faces do not show.
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Approach: outside-faces of the block
- Each cube has surface area 24, so each face is 4 and the edge is 2.
- The four cubes form a 2 by 2 by 1 block, measuring 4 by 4 by 2.
- Its surface area is 2(4x4) + 4(4x2) = 32 + 32 = 64 cm².
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