How Many Liters of Paint Needed for Pyramid?

  • Thread starter smartguy_ppl
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In summary, the base of the pyramid is made up of 100 blocks by 100 blocks, with each successive layer being one less block wide and deep. The top layer consists of just one block. Each block has dimensions of 97 cm by 97 cm by 63 cm. To coat the entire exposed surface of the pyramid, we must first calculate the total surface area. For the sides of the blocks, the sum of squares of the first 100 numbers is multiplied by 97 cm and the height of 63 cm, then divided by 10,000 and multiplied by 4 (for the four sides of the pyramid). This gives us a total of 4,114.74 liters of paint. For the top of
  • #1
smartguy_ppl
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The base of the pyramid is 100 blocks by 100 blocks; each successive layer is one less block wide and deep, until the top layer which is simply one block. Each block is 97 cm wide by 97 cm deep by 63 cm tall.

If one liter of paint can coat exactly three square meters, how many liters are required to coat the entire exposed surface of the pyramid? Round up to the nearest liter.

I know what to do but is there a "pattern" that can be used here?

EDIT:
Paint Used For Side of Blocks:
1+2+3...+100
= 5050 x width of 97 x height of 63 x 4 sides of a pyramid
= 123,442,200 cm2 / 10 000
= 12,344.22 m2 / 3
= 4114.74 litres of paint

Paint Used For Top of Blocks:
1+2+3...+100
= (100 x 100) (97 x 97)
= 94090000 cm2 / 10 000
= 9409 m2 / 3
= 3136.33

Total:
4114.74 + 3136.33
= 7251.07
= 7251 L.

Can I have confirmation that this is right? :smile: =)
 
Last edited:
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  • #2
What is the sum of squares of first 100 numbers? This gives you total periphery. Multiply it with the width and height. You get total exposed surface area. Convert it into sq.mtr.
 
  • #3
To cover the top of all blocks.
So what will you see if you are on the plane, which is above the top of the pyramid, and look straight down the pyramid?
You will see a 100 blocks x 100 blocks rectangle, right?
So what is the area of that rectangle? Is it also the area of the top of all blocks you must paint?
Viet Dao,
 
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  • #4
yes you have to paint the sides of the blcok and the top of the block
 
  • #5
It seems that you got the side of the block correctly, but you got the top of the block incorretly...
First, why are you multiply by 4 (sides of the pyramid)?
And if you calculate like that, you will paint all top of the blocks, not just the ones that are exposed.
Viet Dao,
 
  • #6
Thank you for that comment. I will correct it.
 
  • #7
smartguy_ppl said:
...
Paint Used For Top of Blocks:
1+2+3...+100
= (100 x 100) (97 x 97)
= 94090000 cm2 / 10 000
= 9409 m2 / 3
= 3136.33
Yup. Correct.
But you don't need the 1 + 2 + 3 + ... + 100. :smile:
See the bolded part of the quote.
Viet Dao,
 
  • #8
I am sorry for misguiding.
 

FAQ: How Many Liters of Paint Needed for Pyramid?

1. How do you calculate the volume of a pyramid?

To calculate the volume of a pyramid, you need to multiply the base area by the height and divide the result by three.

2. What is the formula for finding the area of a pyramid's base?

The formula for finding the area of a pyramid's base varies depending on the shape of the base. For example, the area of a square base is equal to the length of one side squared, while the area of a triangular base is equal to half the base length multiplied by the height.

3. How many sides does a pyramid have?

A pyramid has a minimum of four sides, but can have any number of sides depending on the shape of its base. For example, a square pyramid has five sides, while a pentagonal pyramid has six sides.

4. How many liters of paint are needed to cover a pyramid?

The amount of paint needed to cover a pyramid depends on the surface area of the pyramid and the type of paint being used. You can calculate the surface area by finding the areas of each face and adding them together. Then, divide the surface area by the coverage area of the paint to determine the number of liters needed.

5. Can you use the same formula for finding the volume of a pyramid with any shape of base?

Yes, the formula for finding the volume of a pyramid can be used for any shape of base. As long as you know the area of the base and the height of the pyramid, you can calculate the volume using the formula.

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