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hi

Added 7/20/2011 2:40:48 AM

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helloo

Added 9/22/2011 2:16:50 PM

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fvck you

Added 9/22/2011 2:17:31 PM

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i dont want to

Added 9/22/2011 2:18:14 PM

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ok

Added 9/22/2011 2:18:29 PM

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1) to find the surface area of the pyramid, you will need the area of the 4 triangles and the base
find the area of the base
since the perimeter of the base is 40
each side will be 10 cz [40/4 =10]
the area of a square is length x width [ l x w]
10 x 10 = 100
*the area of the base is 100 square inches
now, find the area of the 4 triangles
this will be quite confusing cz it involve with visualizing a pyramid
we know that the height is 12 inches and one side of the base is 10
imagine u are looking through a pyramid, the height will be at the middle [ the center of the base connecting to the sharp corner at the top ]
now imagine that there is a triangle inside the square pyramid
the height of the triangle is the height of the pyramid, the base of the triangle is half the length of the one side of the base, the hypothuse of the triangle is the slant height of one of the triangles of the pyramid
what i just wrote is very confusing, it is hard to understand
try to draw it out
do u know what is the slant height?
ignore the triangle that i wrote about before
look back at the pyramid, there are four triangles
the slant height will be the height of a triangle
but the slant height is the hypothuse for the triangle inside
the one that i told u to visualize
ALL THat trash that i talk about is very confusing and may not be helpful to u, anyway i will continue to find the surface area of pyramid
okay, now we have the area of the base which is 100 square inches
we need to find the area of one triangle
talking back to the imaginary triangle inside the pyramid
find the slant height
the height is 12, the base of triangle is 5 cz [the base is half the length of one side of the pyramid which is 10/2]
now we find the hypothuse/slant height
12^2 + 5^2= 144 + 25 = 169
square root of 169 = 13
*13 is the slant height
looking back at the non-imaginary triangle
we know the height of the triangle is 13 and the base is 10
the area of ONE triangle is (13 x 10) / 2 = 65 square inches
the area of the FOUR triangles is 65 x 4 = 260
*****the SURFACE area is 260 +100= 360 square inches
2)
volume of the pyramid is (1/3)bh
base is 10
height is 12
plug in those in the equation
(1/3) x 10 x 12 = (1/3) x 120 = 40
*** volume = 40 cubic inches
i don't think i helped but i tried =]

Added 9/22/2011 3:00:58 PM