All categories

2 years ago

What is the area of a regular pentagon with side length 20 feet? Can u guys show steps pls.

Mathematics

1 answer:

ivann1987 [24]2 years ago

4 0

Answer:

$688.19m^2$

Step-by-step explanation:

$A=\frac{1}{4} \sqrt{5(5+2\sqrt{5} } a^2\\=\frac{1}{4} \sqrt{5(5+2\sqrt{5} }* 20^2\\=688.19096m^2\\=688.191m^2\\=688.19m^2$

You might be interested in

A Gallup survey of 2322 adults (at least 18 years old) in the U.S. found that 408 of them have donated blood in the past two yea

Lelu [443]

Answer: aA 90% confidence interval for the population proportion of adults in the U.S. who have donated blood in the past two years = (0.163,0.189)

Step-by-step explanation:

Let p = population proportion of adults in the U.S. who have donated blood in the past two years.

Given: A Gallup survey of 2322 adults (at least 18 years old) in the U.S. found that 408 of them have donated blood in the past two years.

Sample size: n= 2322

Sample proportion $q=\dfrac{408}{2322}=0.176$

Critical z-value for 90% confidence level : z*=1.645

The confidence interval for population proportion:

$q\pm z^*(\sqrt{\dfrac{q(1-q)}{n}})$

A 90% confidence interval for the population proportion of adults in the U.S. who have donated blood in the past two years:

$0.176\pm (1.645)(\sqrt{\dfrac{0.176(1-0.176)}{2322}})\\\\=0.176\pm (1.645)(0.0079)\\\\=(0.176\pm0.013)\\\\=(0.176-0.013,0.176+0.013))\\\\=(0.163,0.189)$

Hence,

6 0

3 years ago

Consider the line given by the equation: 2x - y= -2

Klio2033 [76]

Answer:

Step-by-step explanation:

look at 2=x-y=2

move this term to the left (2)

it becomes 2=x-y+2=0

and thats your results

Examples: x^2-2x=-1, 3x-x-x+a-a=5, (x^2-1)/(x+1), 2x-(x+x)

7 0

3 years ago

I’m doing operations and interfers Need the answer have a test tmr

arsen [322]

Answer:

all work for both worksheets are pictured and shown

Step-by-step explanation:

worksheet 2

28. 968/22=44

29. 27+8=35

30. 39×37=-1443

5 0

3 years ago

What is the sum of the geometric sequence 1, 4, 16, ... if there are 8 terms?

mylen [45]

Answer:

1, 4, 16, 64, 256, 1024, 4096, 16384

Step-by-step explanation:

Multiply by 4

6 0

2 years ago

Identify the factors of x2 − 4x − 21. (x − 7)(x 3) (x 7)(x − 3) (x 21)(x − 1) (x − 21)(x 1)

Tanzania [10]

The factors of the quadratic expression x² - 4x - 21 is (x - 7)(x + 3), making the first option the right choice.

A quadratic expression is of the form ax² + bx + c, which can be factorized using the mid-term factorization method, where b is shown as the sum or difference of two such numbers, whose product is equal to the product of a and c.

In the question, we are asked to factorize the quadratic expression, x² - 4x - 21.

In the given expression, a = 1, b = -4, and c = -21.

Thus, ac = -21.

The numbers having a product 21 are:

1*21 = 21,

3*7 = 21.

Since, 3 - 7 = -4 (That is b), we break b into 3 and -7.

Thus, the expression can now be shown as:

x² - 4x - 21

= x² + (3 - 7)x - 21

= x² + 3x - 7x - 21

= x(x + 3) - 7(x + 3) {By taking common}

= (x - 7)(x + 3) {By taking common}.

Thus, the factors of the quadratic expression x² - 4x - 21 is (x - 7)(x + 3), making the first option the right choice.

Learn more about factorizing a quadratic expression at

brainly.com/question/52959

#SPJ1

5 0

1 year ago