surface area

A

algray09

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so I am having trouble finding the surface area of a prism in on of the problems in my homework. the equation my teacher gave is 2(B)+PH. the perimeter of the problem is 12, height is 50, and base is 9. when I did the equation I got 618 as the surface area. so how do I get the surface area of this problem?
 
algray09 said:
so I am having trouble finding the surface area of a prism in on of the problems in my homework. the equation my teacher gave is 2(B)+PH. the perimeter of the problem is 12, height is 50, and base is 9. when I did the equation I got 618 as the surface area. so how do I get the surface area of this problem?
Click to expand...
Please post the problem.
 
algray09 said:
so I am having trouble finding the surface area of a prism in on of the problems in my homework. the equation my teacher gave is 2(B)+PH. the perimeter of the problem is 12, height is 50, and base is 9. when I did the equation I got 618 as the surface area. so how do I get the surface area of this problem?
Click to expand...
What is B?

What is P?

What is H?

Please show us what you have tried and exactly where you are stuck.

Please follow the rules of posting in this forum, as enunciated at:

https://www.freemathhelp.com/forum/threads/read-before-posting.109846/#post-486520

Please share your work/thoughts about this assignment.
 
the problem is find the surface area of the blue shape (not the light blue).
B=9 P=12 H=50
the equation I used was 2(B)+PH which is the equation the teacher told the class to use if the shape is a prism, so I did 2(9)+12(50) and I got 618 but when I plugged in that answer it said it was wrong. I was wondering if I missed a step in the equation or used the wrong equation.
here's the pages:
 

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algray09 said:
the problem is find the surface area of the blue shape (not the light blue).
B=9 P=12 H=50
the equation I used was 2(B)+PH which is the equation the teacher told the class to use if the shape is a prism, so I did 2(9)+12(50) and I got 618 but when I plugged in that answer it said it was wrong. I was wondering if I missed a step in the equation or used the wrong equation.
here's the pages:
Click to expand...
I get 618 too.
More importantly, do you understand the formula and why it works?
 
yeah and I now realized what I forgot since its a composite figure I had to subtract a base from the answer to get the correct answer. so what did to get it correct was 618-9 to get 609. which 609 is the correct answer.
 
algray09 said:
yeah and I now realized what I forgot since its a composite figure I had to subtract a base from the answer to get the correct answer. so what did to get it correct was 618-9 to get 609. which 609 is the correct answer.
Click to expand...
I don't know... If you were specifically told to disregard one of the faces - fine. Otherwise, I would object to such interpretation.
 
lev888 said:
I don't know... If you were specifically told to disregard one of the faces - fine. Otherwise, I would object to such interpretation.
Click to expand...
The problem asked for the surface area of the "blue" - which has five exposed faces. The sixth face is hidden due to the existence of the pyramid on top.
 
Subhotosh Khan said:
The problem asked for the surface area of the "blue" - which has five exposed faces. The sixth face is hidden due to the existence of the pyramid on top.
Click to expand...
I would understand if it asked for exposed faces. It didn't. It asked about the blue shape. A shape remains a shape if you put another shape on top of it. And what kind of shape do we get if we subtract one face? An open volume? In this case shouldn't "interior" sides of those surfaces be included in the surface area?
 
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