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13 votes
13 votes
Pls helpp

I dont understand this

Pls helpp I dont understand this-example-1
User ABOS
by
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1 Answer

12 votes
12 votes

Answer:

third expression

Explanation:

the surface area (SA) is the area of the 6 faces.

Note that opposite faces are congruent.

the surface area is the the area of each face multiplied by 2 , since they are congruent.

SA = 2(front area ) + 2(side area ) + 2(area of base)

= 2(5 × 7 ) + 2(4 × 7 ) + 2(4 × 5 ) ← third option

= 2(35) + 2(28) + 2(20)

= 70 + 56 + 40

= 166 cm²

User Jdi
by
2.6k points
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