## ErinWeeks Group Title Find the surface area of the figure to the nearest whole number. PLEASE HELPPPP one year ago one year ago

1. ErinWeeks Group Title

A. 310 ft2 B. 158 ft2 C. 135 ft2 D. 74 ft2 I thought it was C but it was wrong -_-

2. ankolix Group Title

the back side in the image is very confusing :/

3. ErinWeeks Group Title

its 2.5 and 3.3

4. JayDS Group Title

hint: split it into two objects. find the surface area of the top triangle pyramid and add it to the surface area of the square prism

5. ErinWeeks Group Title

im still confused

6. JayDS Group Title

but you understand what I said?

7. ErinWeeks Group Title

i dont really -_-

8. JayDS Group Title

k wait, let me work through the whole thing first then I'll explain it to you.

9. ErinWeeks Group Title

okay thank you

10. JayDS Group Title

|dw:1357770316535:dw| see I split the two? this is what I meant and excuse my drawing. Note: we do not need to find the bottom base of the pyramid and top of the square prism, as it is not accounted towards the total surface area. (It's the part where they are glued together if you may).

11. ankolix Group Title

well i can to see 2 solids... the piramid and the cube.. so the piramid area is $\frac{ 1 }{ 2 }* perimetre*face length$. in your piramid $\frac{ 1 }{ 2 } \times 18\times 3.3$ and the cube surface

12. ErinWeeks Group Title

for the second formula i got 29.7 ... i dont know how to do the 1st one

13. JayDS Group Title

yes 29.7 is right for the top(pyramid).

14. ErinWeeks Group Title

okay now can you explain how to do the bottom

15. JayDS Group Title

for the bottom(square prism) it is even easier. 2(4.5 x 6 + 4.5 x 6) + (4.5 x 4.5)

16. JayDS Group Title

this is because the top of the square prism(where it needs to be used to be stuck against the bottom part of the pyramid) is not accounted for.

17. ErinWeeks Group Title

i got 74.25 now what ??

18. JayDS Group Title

19. JayDS Group Title

20. ErinWeeks Group Title

i got 103.95 but thats not a choice

21. JayDS Group Title

your 74.25 you got is wrong, try again.

22. JayDS Group Title

it should be 128.25

23. ankolix Group Title

no, it is $4(4.5*6)+ 2(4.5*4.5)$

24. ErinWeeks Group Title

with @ankolix formula i got 142.5

25. JayDS Group Title

@ankolix I don't think you understand the concept that you only need 4.5 x 4.5 once not twice.

26. ErinWeeks Group Title

27. ankolix Group Title

yeah.. ivemistake

28. JayDS Group Title

29. ErinWeeks Group Title

A. 310 ft2 B. 158 ft2 C. 135 ft2 D. 74 ft2

30. JayDS Group Title

and you made a calculation error before, so please be careful when entering it in the calculator.

31. ankolix Group Title

is 4(4.5*6)+(4.5*4.5)+29.7=157.95.. option B

32. JayDS Group Title

yep, option B.

33. JayDS Group Title

using my calculation you will get 157.95. and why is it not exact? because probably when they calculated they used more decimal places which resulted them to get a more accurate answer but we have been only given that, so we just those figures in the picture.

34. ankolix Group Title

medal for gratitude ;)

35. ErinWeeks Group Title

okay thank you so muchh..

36. JayDS Group Title

@ankolix, I would like to say you deserve the medal for trying but you have copied off me but good job.