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The prism below is being wrapped for Christmas. How many square feet will Mrs. Harris need to wrap the prism ?

The prism below is being wrapped for Christmas. How many square feet will Mrs. Harris-example-1
User Tim Seed
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1 Answer

8 votes
8 votes

We need to calculate the surface area

We have 6 faces and three different rectangles

The red rectangles are equals

The green rectangles are equals

The blue rectangles are equals

The formula for the area of a rectangle is


A=l* w

where

l is the length

w is the width

The area for one red rectangle

l=10

w=5


A_R=10*5=50

The area for one green rectangle is

l=10

w=7


A_G=10*7=70

The area for one blue rectangle

l=7

w=5


A_B=7*5=35

The total area is


A=2A_R+2A_G+2A_B=2(50)+2(70)+2(35)=100+140+70=310in^2

Then we need to transform the square inches to square feet

1 square ft = 144 square inches

x square ft = 310 square inches


x=(310)/(144)=2.15\text{ }

Mrs Harris will need 2.15 square ft to wrap the prism

The prism below is being wrapped for Christmas. How many square feet will Mrs. Harris-example-1
User BeeOnRope
by
3.1k points