Respuesta :
r = m - v + 2, where r = faces, v = vertices, and m = edges
r = 28 - 13 + 2
r = 15 + 2
r = 17, so the first answer is correct.
7. The surface area of a cone is A = pi*r*sqrt(r^2 + H^2)
A = pi*(7)(sqrt(49 + 1849)
A = pi*(7)(43.57)
A = pi*305 = 959 m^2, so the first answer is correct.
13. The volume of the slab is V = HLW
V = (5 yards)(5 yards)(1/12 yards)
V = 25/12 cubic yards
So it costs $46.00*(25/12) = $95.83 of total concrete. The third answer is correct.
21. First, find the volume of the rectangular prism. V = HLW
V = (15 cm)(5 cm)(7 cm)
V = 525 cm^3
Next, find the volume of the pyramid. V = 1/3(BH), where H is the height of the pyramid and B is the area of the base of the pyramid. Note that B = (15 cm)(5 cm) = 75 cm^2
V = (1/3)(75 cm^2)(13 cm)
V = 325 cm^3
Add the two volumes together, the total volume is 850 cm^3. The fourth answer is correct.
22. The volume of a square pyramid is V = 1/3(S^2)(H), where S is the side length and H is the height.
V = (1/3)(20^2 in^2)(21 in)
V = 2800 in^3
Now that we know the volume of this pyramid, and that both pyramids have equal volume, we plugin our V to the equation for the volume.
2800 = (1/3)(84)(S^2)
2800 = 28S^2
100 = S^2
10 in = S, so we have a side length of 10 in, and the first answer is correct.
r = 28 - 13 + 2
r = 15 + 2
r = 17, so the first answer is correct.
7. The surface area of a cone is A = pi*r*sqrt(r^2 + H^2)
A = pi*(7)(sqrt(49 + 1849)
A = pi*(7)(43.57)
A = pi*305 = 959 m^2, so the first answer is correct.
13. The volume of the slab is V = HLW
V = (5 yards)(5 yards)(1/12 yards)
V = 25/12 cubic yards
So it costs $46.00*(25/12) = $95.83 of total concrete. The third answer is correct.
21. First, find the volume of the rectangular prism. V = HLW
V = (15 cm)(5 cm)(7 cm)
V = 525 cm^3
Next, find the volume of the pyramid. V = 1/3(BH), where H is the height of the pyramid and B is the area of the base of the pyramid. Note that B = (15 cm)(5 cm) = 75 cm^2
V = (1/3)(75 cm^2)(13 cm)
V = 325 cm^3
Add the two volumes together, the total volume is 850 cm^3. The fourth answer is correct.
22. The volume of a square pyramid is V = 1/3(S^2)(H), where S is the side length and H is the height.
V = (1/3)(20^2 in^2)(21 in)
V = 2800 in^3
Now that we know the volume of this pyramid, and that both pyramids have equal volume, we plugin our V to the equation for the volume.
2800 = (1/3)(84)(S^2)
2800 = 28S^2
100 = S^2
10 in = S, so we have a side length of 10 in, and the first answer is correct.
The missing number using Euler's formula is: Option A. 17
The maximum volume of a square pyramid is: Option B. 4,608
What is Euler's formula?
"It is a geometrical formula. V − E + F = 2, where V represents number of vertices, E represents number of edges and F represents number of faces."
What is square pyramid?
"Square pyramid is a three dimensional geometrical figure where four triangular sides are associated to square base."
What is cube?
"A cube is a three-dimensional geometric structure with six congruent square face."
Formula for volume of a square pyramid:
[tex]V=\frac{1}{3}a^{2}h[/tex]
where [tex]a[/tex] represents the length of square base and [tex]h[/tex] represents the height of the pyramid.
Consider the first question,
number of vertices (V) = 13
number of edges (E) = 28
So, using Euler's formula:
[tex]13-28+F=2[/tex]
⇒ [tex]-15+F=2[/tex]
⇒ [tex]F=2+15[/tex]
⇒ [tex]F=17[/tex]
So, the number of faces are 17.
Hence, the correct answer is option A. 17
Consider last question,
the side length of a cube = 24 cm
As the square pyramid fit inside a cube.
⇒ the length of the square base of a pyramid [tex]b[/tex] = 24 cm
and the height of a square pyramid [tex]h[/tex] = 24 cm
So, the volume of a square pyramid is,
[tex]V=\frac{1}{3} a^{2} h[/tex]
⇒ [tex]V=\frac{1}{3}[/tex] × [tex]24^{2}[/tex] × [tex]24[/tex]
⇒ [tex]V= 4608[/tex] [tex]cm^{3}[/tex]
Therefore, the maximum volume of a square pyramid that can fit inside a cube with a side length of 24 cm is [tex]4608[/tex] [tex]cm^{3}[/tex].
And the correct answer is option B. 4,608
Learn more about Euler's formula here,
https://brainly.com/question/22069428
Learn more about volume of a square pyramid here:
https://brainly.com/question/2501401
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