Regina’s work to find the surface area of a square pyramid from its net is shown below.


A square pyramid. The square base has side lengths of 9.4 inches. The triangular sides have a height of 11.9 inches.

Surface area of the pyramid = 4 (one-half (9.4) (12.8)) + 9.4 squared = 329 square inches


What error did Regina make?

She should have used One-half (9.4) (11.9) to represent the area of a single triangle.

She should have multiplied all the terms inside the parentheses by 4 when she simplified.

She should have used One-half (4.7) (12.8) to represent the area of a single triangle.

She should have used a different collection of shapes as the net of the pyramid.

keeping in mind that perpendicular lines have negative reciprocal slopes, let's check for the slope of the equation above

[tex]5x-y=-7\implies 5x-y+7=0 \\\\\\ \stackrel{\stackrel{m}{\downarrow }}{5} x+7=y\qquad \impliedby \begin{array}{|c|ll} \cline{1-1} slope-intercept~form\\ \cline{1-1} \\ y=\underset{y-intercept}{\stackrel{slope\qquad }{\stackrel{\downarrow }{m}x+\underset{\uparrow }{b}}} \\\\ \cline{1-1} \end{array}[/tex]

so a line perpendicular to that one above will have a slope of

[tex]\stackrel{~\hspace{5em}\textit{perpendicular lines have \underline{negative reciprocal} slopes}~\hspace{5em}} {\stackrel{slope}{5\implies \cfrac{5}{1}} ~\hfill \stackrel{reciprocal}{\cfrac{1}{5}} ~\hfill \stackrel{negative~reciprocal}{-\cfrac{1}{5}}}[/tex]

Based on the above, it can be inferred that the best option to produce the 15,000 units is the factory with the lowest cost per unit.

Unit cost is a term to refer to the value per unit of a product that a factory charges to produce it.

In this case, the best alternative to produce 15,000 products is the factory with the lowest cost per unit, since this will reduce the cost of the order.

To find the cost per unit we divide the total cost of the order by the number of units. For example:

To know which one is more convenient, I must divide the total value by the number of units

According to the above, the second option would be the cheaper.

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Answer:

.53 facory B

Step-by-step explanation:

10000/15000 =.66

8000

Answer:

∠ QPR = 125°

Step-by-step explanation:

the angles subtended by 2 congruent arcs are congruent , that is

5x = 4x + 25 ( subtract 4x from both sides )

x = 25

Then

∠ QPR = 4x + 25 = 4(25) + 25 = 100 + 25 = 125°

Answer:

Step-by-step explanation:

The triangles are congruent when corresponding sides are congruent.

__

ΔFGH ≅ ΔABC means corresponding sides are ...

  (GH, BC) = (V, 16)

  (HF, CA) = (48, W)

Corresponding sides being congruent means ...

  V = 16

  W = 48

Answer: -6, -7

Magnitude = 9.22

Step-by-step explanation:

Answer:

Step-by-step explanation:

The confidence interval (CI) is a range of values that, with a particular level of confidence, is likely to include a population value. The confidence interval for the given sample is 48.07656, 45.9234.

The confidence interval (CI) is a range of values that, with a particular level of confidence, is likely to include a population value. The percentage is used to represent the location of a population mean between an upper and lower interval.

Given the random sample is 81, while the sample means is 47, the standard deviation is 5.89. Therefore, the confidence interval for 90% of the population mean is,

[tex]CI = \bar{x} \pm z \dfrac{s}{\sqrt{n}}\\\\CI = 47 \pm 1.645 \dfrac{5.89}{\sqrt{81}}\\\\CI= 47 \pm 1.07656\\\\CI = 48.07656, 45.9234[/tex]

Hence, the confidence interval for the given sample is 48.07656, 45.9234.

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Answer:

Dimensions:  150 m x 150 m

Area:  22,500m²

Step-by-step explanation:

Given information:

Let [tex]x[/tex] = width of the field

Let [tex]y[/tex] = length of the field

Create two equations from the given information:

  Area of field:   [tex]A= xy[/tex]

  Perimeter of fence:   [tex]2(x + y) = 600[/tex]

Rearrange the equation for the perimeter of the fence to make y the subject:

[tex]\begin{aligned} \implies 2(x + y) & = 600\\ x+y & = 300\\y & = 300-x\end{aligned}[/tex]

Substitute this into the equation for Area:

[tex]\begin{aligned}\implies A & = xy\\& = x(300-x)\\& = 300x-x^2 \end{aligned}[/tex]

To find the value of x that will make the area a maximum, differentiate A with respect to x:

[tex]\begin{aligned}A & =300x-x^2\\\implies \dfrac{dA}{dx}& =300-2x\end{aligned}[/tex]

Set it to zero and solve for x:

[tex]\begin{aligned}\dfrac{dA}{dx} & =0\\ \implies 300-2x & =0 \\ x & = 150 \end{aligned}[/tex]

Substitute the found value of x into the original equation for the perimeter and solve for y:

[tex]\begin{aligned}2(x + y) & = 600\\\implies 2(150)+2y & = 600\\2y & = 300\\y & = 150\end{aligned}[/tex]

Therefore, the dimensions that will give Tanya the maximum area are:

150 m x 150 m

The maximum area is:

[tex]\begin{aligned}\implies \sf Area_{max} & = xy\\& = 150 \cdot 150\\& = 22500\: \sf m^2 \end{aligned}[/tex]

Answer:

Points on the inverse are [tex](1,-1), (4,2), \text{and } (0,0)[/tex]

Step-by-step explanation:

When writing the inverse function of a set of points, you simply switch the coordinates:

[tex]\text{Function}: (x,y)\\\text{Inverse}: (y,x)[/tex]

We are given the points

[tex](-3,9), (-1,1), (0,0), \text{and } (2,4)[/tex]

Using our rule for function, our new points will be

[tex](9,-3), (1,-1), (0,0), \text{and } (4,2)[/tex]

From the list, the points we have for the graph of the inverse are

[tex](1,-1), (4,2), \text{and } (0,0).[/tex]

Answer:

17

Step-by-step explanation:

at f(7) means x is 7

7+10 is 17

Answer: its c

Step-by-step explanation: im a smarty boy i hope u its right or not

Answer:

The bird's speed is 50mph.

The bird's feeder is 25 miles away.

Step-by-step explanation:

10/6=x/30

6*x=30 is 6/30=x

x=5

6*5=30 so 10*5=50

x=50

mph/time=distance per hour

50/(1/2)=25 miles

Answer:

A got it right

Step-by-step explanation:

got it right

The scenario that could be accurately modeled using this diagram is B. Juan Victor gave a 25% gratuity of $12 on a bill that was $48.

Here is the remainder of the question:

Which of the following scenarios could be accurately modeled using this diagram?

Juan Victor gave a gratuity of $25 on a bill that was $48.

Juan Victor gave a 25% gratuity of $12 on a bill that was $48.

Juan Victor gave a gratuity of $12 on a bill that was $100.

Juan Victor gave a 12% gratuity on a bill that was $25.

A conceptual model is a representation of a system to help people understand a subject the model represents.

In this case, the scenario that could be accurately modeled using this diagram is that Juan Victor gave a 25% gratuity of $12 on a bill that was $48.

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Answer: The area of a triangle is the region enclosed between the sides of the triangle. Area of ΔABC = 1/2 × Base × Height

Step-by-step explanation:

Area of ΔABC= 1/2 × Base × Height = 1/2 × h × BC

If ABC is an equilateral triangle, Area of ΔABC = (√3/4)a2 where a is the length of a side of the equilateral triangle.

Thus, we have seen the formula and definition of the area of triangle ABC.

Answer:

9 units

Step-by-step explanation:

Using Pythagorean Theorem

12^2 + x^2 = 15^2

144 +x^2 = 225

x^2 = 81

x = 9

Answer:

Objects mostly have one or more geometrical shapes like the following. These types of shapes are called three dimensional (3-D) shaped solids. All these geometrical shapes have faces. We have learned about faces like triangular faces, rectangular face, square face and circular face.

Answer:

59 degrees

Step-by-step explanation:

Angles on a straight line add up to 180 degrees

Angles in a triangle add up to 280 degrees

180 minus 149 is 31

31 add 90 is 121

180 minus 121 is 59

Answer:

341 cm²

Step-by-step explanation:

Formula :

Surface area = Area of 4 triangle faces + Area of square base

===============================================================

Solving :

⇒ Surface area = 4 × 1/2 × 11 × 10 + 11²

⇒ Surface area = 2 × 110 + 121

⇒ Surface area = 220 + 121

⇒ Surface area = 341 cm²

The surface area of the square pyramid is 341 square centimeter.

a three dimensional shape can be defined as a solid figure or an object or shape that has three dimensions—length, width, and height.

The surface area of a square pyramid is calculated by the equation S = B + 1/2 × P × S

where B is the area of the base,

P is the perimeter of the base, and

S is the slant height of the pyramid.

the area of the base =11×11

B=121 square centimeter

The perimeter of the base = 2(11+11)

P= 44 cm

Slant height (S) is 10 cm.

Surface Area = 121 + 1/2 (44×10)

=121+220

=341 square centimeter

Hence,  the surface area of the square pyramid is 341 square centimeter.

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to get the equation of any straight line, we simply need two points off of it, so let's use the ones provided in the table above.

[tex]\begin{array}{|cc|ll} \cline{1-2} \stackrel{millions}{population}&year\\ \cline{1-2} 161&1950\\ 291&2000\\ \cline{1-2} \end{array}\hspace{5em} (\stackrel{x_1}{161}~,~\stackrel{y_1}{1950})\qquad (\stackrel{x_2}{291}~,~\stackrel{y_2}{2000}) \\\\\\ \stackrel{slope}{m}\implies \cfrac{\stackrel{rise} {\stackrel{y_2}{2000}-\stackrel{y1}{1950}}}{\underset{run} {\underset{x_2}{291}-\underset{x_1}{161}}} \implies \cfrac{ 50 }{ 130 }\implies \cfrac{5}{13}[/tex]

[tex]\begin{array}{|c|ll} \cline{1-1} \textit{point-slope form}\\ \cline{1-1} \\ y-y_1=m(x-x_1) \\\\ \cline{1-1} \end{array}\implies y-\stackrel{y_1}{1950}=\stackrel{m}{\cfrac{5}{13}}(x-\stackrel{x_1}{161}) \\\\\\ y-1950=\cfrac{5}{13}x-\cfrac{805}{13}\implies y=\cfrac{5}{13}x-\cfrac{805}{13}+1950\implies y=\cfrac{5}{13}x+\cfrac{24545}{13}[/tex]

Answer:

  410 g

Step-by-step explanation:

Radioactive decay can be modeled by an exponential equation. The amount remaining (y) after a time period (t) can be expressed in terms of the initial amount (a) and the half-life (h).

  y = a(1/2)^(t/h)

__

We can use this equation with the given values to find the amount remaining.

  y = (680 g)(1/2)^((19 yrs)/(26 yrs)) ≈ (680 g)(0.602583)

  y ≈ 410 g

About 410 grams of element X will remain after 19 years.

The probability that the next elk that will be caught will be unmarked is 5400/ 5625, 0.96 and 96%

The probability that the next wolf that will be caught will be unmarked is 696 / 928,  0.75 and 75%.

Probability determines the odds that a random event would happen. The probability the event occurs is 1 and the probability that the event does not occur is 0.

The probability that the next elk that will be caught will be unmarked = number of unmarked elks / total number of elks

number of unmarked elks  = 5625 - 225 = 5400

5400/ 5625 = 0.96 = 96%

The probability that the next wolf that will be caught will be unmarked = number of unmarked wolfs / total number of wolfs

number of unmarked wolfs  = 928 - 232 = 696

696 / 928 =  0.75 =  75%.

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======================================================

Work Shown:

[tex]a = 12\\\\b = 19\\\\c = 20\\\\a^2+b^2 = 12^2+19^2 = 505\\\\c^2 = 20^2 = 400\\\\[/tex]

The values of [tex]a^2+b^2[/tex] and [tex]c^2[/tex] are not the same number

Therefore, there's no way that [tex]a^2+b^2 = c^2[/tex] is possible, which means we do not have a right triangle.

Put another way: since [tex]a^2+b^2 \ne c^2[/tex], this means we don't have a right triangle.

Refer to the converse of the pythagorean theorem for more information.

Side note: because of that same theorem, and because [tex]a^2+b^2 > c^2[/tex] is the case, this means we have an acute triangle based on what is shown below.

We know the slope formula

Parallel lines have equal slope so it has m=-2

Answer:

12

Step-by-step explanation:

127491733816383827i 9273

Answer:

f(x) = 3x + 9:  y - intercept is option  c. (0,-9)

f(x) = 3x - 9:  y - intercept is option   b. (0, 9)

Step-by-step explanation:

option a and d cant be correct since y = 0 in those answer when the y - intercept is when x = 0

If the function f(x) = 3x + 9

than x = 0

f(x) = 3(0) + 9

f(x) = 0 + 9

f(x) = 9

x = 0 and y = 9 (0, 9)

If the function f(x) = 3x - 9

than x = 0

f(x) = 3(0) - 9

f(x) = 0 - 9

f(x) = -9

x = 0 and y = -9 (0, -9)

Step is the same when constructing an inscribed regular hexagon and an inscribed equilateral triangle is shown below:

Geometric construction is the process of drawing a geometrical figure using two geometrical instruments, a compass, and a ruler.

Construction of an inscribed regular hexagon

1) Set compass width to the radius of the circle

2) Make an arc on the circle with the set radius.

3) From the previous arc draw another arc with the same radius.

4) Continue this process for the other vertex.

5) Connect all the vertices.

Construction of an inscribed equilateral triangle

1) Set compass width to the radius of the circle

2) Make an arc on the circle with the set radius.

3)From the previous arc draw another arc with the same radius.

4)Continue this process for the other vertex.

5) Connect the every other vertices point by drawing  a line between every other adjacent vertex point to form an inscribed equilateral triangle.

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Answer:

1/2

Step-by-step explanation:

1. 4 1/2- 2 1/2= 2

2. 2+1=3

3. 3-2 1/2= 1/2

He has enough