I need somebody to help explain this question to me: (SC will be posted below) The volume of a right triangular prism is 72 cubic feet. The height of the prism is 9 feet. The triangular base is an isosceles right triangle. A right triangular prism has a volume of 72 cubic feet. Triangles A E C and B F D are the base triangles. Sides F D and B F are congruent and form a right angle. The height of the prism is 9 feet. What is the area of the triangular base? 16 square feet What is the length of edge DF? 8 feet
(I left guesses)
What I have to go off of: The height is 9, which would be the tallest point on the triangular prism, which is BF. The image shows that BF=DF, so DF should also be 9 meaning that the area should be (9*9)/2, but it is not that
@snowflake0531
Volume is base times height, so base times 9 equals 72 So what's base?
CDEF is the base
DBF?
An easy way to find is to imagine... what 2-D shape stacked up together will create that prism, in this case, it's the triangle, so yes DBF
What I was given says that the height is 9, and since bf is the tallest point it is 9
right?
...no
Since you already know that base is DBF... height would be AB/CD/EF, (they're all the same length)
ok
So what's the area of the base if base times 9 is 72
plugging 9*x=72 in my graphing calculator says 8
damn, you used a calculator but yes, it's 8 So now \[\frac{x^2}{2}=8\\x^2=16\] so what's the x
solve the square root of 16 to get 4, x would then be 4
yes
so do you get your answers now?
yep, thanks
yw~
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