Post 12, question 4

For the question number 4 we have to find the total surface area of the plastic that we need to make our exact desk tidy.  So I've decided that I'm going to find the surface area of each piece and then add all of them together.

1)because my top boxes are made of stripes and bottoms. So I have to find the surface area of a stripe and then the SA of the 'bottom parts' and add them together.

 top box on the left:

Length= 7.5+6.5+7.5+6.7

= 28.2 cm

SA= L * W

SA= 28.2 * 3.1

= 87.42 (square cm) 

2)Top box on the right:

Length= 10.5*2+6.5*2

=34 cm

SA= L*W

SA=34*3.1

=105.4 (square cm)

3)Left box on the bottom:

Length= 9.5+7+9.5+7

=33 cm

SA= L*W

SA=33*3.1

=102.3 (square cm)

4)Right box on the bottom:

Length=7.55+6.2+7.8+6.5

=28.05

SA= L*W

=28.05*3.1

=86.96 (square cm)

 

5)To find the SA of all the stripes, I have to add all the SA's together

SA of all the stripes= 87.42+105.4+102.3+86.96

=382.08

6)The SA of top 'floor'

15.4*6.4=98.56 (square cm)

7)The SA of a support thing that holds top boxes in a right place:

13*8=104 (square cm)

8)The SA of the back wall:

20.3*18=365.4 (square cm)

9)The SA of the base:

10.5*18=189 (square cm)

10)To find the total surface area (TSA), I have to add all the previous SA together.

TSA= 382.08+98.56+104+365.4+189

=1139.04 (square cm)

=0.113904 (square m)