Write a two column proof given

kow [346]

There are two acceptable ways of solving this. I'll show both (just in case one of them doesn't align with the information from your textbook).

Option 1 (fast and easy):

The following is the equation for the area of a regular pentagon with side length s.

$A= \dfrac{s^2}{4} \times \sqrt{5(5+2\sqrt{5})}$

Plug s=12 into the equation.

$A= \dfrac{12^2}{4} \times \sqrt{5(5+2\sqrt{5})}$

$\approx 247.7$

The third choice should be your answer.

Option 2 (much more complicated):

The area of a regular polygon can be solved with the following formula.

$A=\dfrac{\text{perimeter} \times \text{apothem}}{2}$

Let's solve for the apothem.

A pentagon can be divided into 5 congruent isosceles triangles. The vertex angle will be 360/5, or 72 degrees.

An isosceles triangle can be divided into two right triangles. One of the angles of the right triangle will be 72/2, or 36 degrees.

The leg opposite of the 36 degree angle will be 12/2, or 6 inches long.

$\text{apothem}=\dfrac{6}{\tan{36}}$

$\approx 8.26$

The apothem is about 8.26 inches.
The perimeter is 12*5, or 60 inches.

$A=\dfrac{\text{perimeter} \times \text{apothem}}{2}$

$=\dfrac{60 \times 8.26}{2}$

$\approx 247.8$

(it seems that we're off by 0.1 due to rounding errors)

The answer is the third choice. Hope this helps! :)

4 0

4 years ago

A 3

Andrew [12]

Answer:

There are (63) combinations. The notation means "six choose three". Out of six items (flavors) choose three.

(nk)=n!k!(n−k)!.

(63)=6!3!3!.

Think of it this way. There are 6 ways to choose a flavor. Once you choose, there are 5 ways to choose the next. After that, there are 4 flavors left. which is 6!/3!=6⋅5⋅4⋅3⋅2⋅13⋅2⋅1=6⋅5⋅4=120.

But, you could have chosen {chocolate,vanilla,strawberry} and you get the same combination as {vanilla, strawberry, chocolate} so we have to divide by 3!=3⋅2⋅1=6 to account for the order of choosing.

So the number of combinations of flavors is (63)=1206=20.

<h3>Mark me a brainlist</h3>

7 0

3 years ago

Answer this qustion plz and if get right i might give you brainlist

nata0808 [166]

Answer:

A

Step-by-step explanation:

SO right off the bat it cannot be c, for they do definatly change.

Next, lets find out how much they change by.

The median would now be 120. Since adding 1 more number would make it just 120. Instead of it being 120+130/2.

This is a decrease of 5. Because we can just subtract normal number by new number: 125-120=5.

Now, the mean is already 500/4. This equals 125.

So lets add 0 to that. So now we must divide it by 1 more number, 4+1=5.

That is 500/5. This equals 100.

This is a decrease of 25. Because we can again subtrasct the normal number by the new number: 125-100=25

That is 5x more of a decrease than the mean.

SO it must be A, since the mean decreased more than the median.

6 0

3 years ago

Help me please I need it by tommrow u get brai nlist

lakkis [162]

Answer:

92905

Step-by-step explanation:

27,500=0.296e

29.6%=0.296

27,500/0.296 =e

e rounded to the nearest whole number is 92,905

4 0

3 years ago

The price per share of stock when the stock market opened on Tuesday was $4.52. The price per share of stock when the stock mark

hjlf

Answer:

From Tuesday to Thursday, the total change in the value of the stock was $-0.36.

There are 3 days from the opening of the stock market on Tuesday and the close of the stock market on Thursday.

The average change in the value of the stock from the opening of the stock market on Tuesday and the close of the stock market on Thursday is $-0.12 per day. This means the stock this amount each day on average.

<u><em>(Sorry if I'm too late.)</em></u>

4 0

3 years ago

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