What is the area of an equilateral triangle having side 'a' units?
​

Answer:

[tex]A=\frac{\sqrt{3}}{4}a^2[/tex]

Step-by-step explanation:

Since an equilateral has all of the sides equal, we can find the height of triangle using: [tex]a^2+b^2=c^2[/tex]. I attached a diagram which should explain how I got the dimensions of the three sides. Using the information from the diagram we get the equation:

[tex]h^2+(\frac{a}{2})^2=a^2[/tex]

Subtract a^2 from both sides

[tex]h^2=a^2-(\frac{a}{2})^2[/tex]

Take the square root of both sides

[tex]h = \sqrt{a^2-(\frac{a}{2})^2}[/tex]

If you know the area of a triangle, it's: [tex]\frac{1}{2}bh[/tex]. In this case the base=a, and the height is what we defined above. Using this we get:

[tex]A = \frac{a}{2}*\sqrt{a^2-(\frac{a}{2})^2}[/tex]

We can distribute the exponent over the division to get:
[tex]A = \frac{a}{2}*\sqrt{a^2-(\frac{a^2}{4})[/tex]

Now we can rewrite a^2 as 4a^2/4

[tex]A = \frac{a}{2}*\sqrt{\frac{4a^2}{4}-(\frac{a^2}{4})[/tex]

Now add the two fractions:

[tex]A = \frac{a}{2}*\sqrt{\frac{3a^2}{4}[/tex]

We can distribute the square root the division just like how we distributed the exponent 2, since the square root can be expressed as an exponent (1/2)

[tex]A = \frac{a}{2}*\frac{\sqrt{3a^2}}{\sqrt{4}}[/tex]

There's a radical identity that states: [tex]\sqrt[n]{a} * \sqrt[n]{b} = \sqrt[n]{a*b}[/tex]. We can use this to rewrite one radical as multiple radicals to simplify it:

[tex]A = \frac{a}{2}*\frac{\sqrt{a^2}*\sqrt{3}}{2}[/tex]

Simplify:

[tex]A = \frac{a}{2}*\frac{a*\sqrt{3}}{2}[/tex]

Now multiply the two fractions

[tex]A = \frac{a^2*\sqrt{3}}{4}[/tex]

This is the formula for the area of an equilateral triangle, but it is also often written as:
[tex]A=\frac{\sqrt{3}}{4}a^2[/tex]

A researcher is conducting a study of charitable donations by surveying a simple random sample of households in a certain city. The researcher wants to determine whether there is convincing statistical evidence that more than 50 percent of households in the city gave a charitable donation in the past year. Let p represent the proportion of all households in the city that gave a charitable donation in the past year. Which of the following are appropriate hypotheses for the researcher?

a. H_o : p=0.5 and H_a:p>0.5
b. H_o:p=0.5 and H_a:p≠0.5
c. H_o:p=0.5 and H_a:p<0.5
d. H_o:p>0.5 and H_a:p≠0.5
e. H_o:p>0.5 and H_a:p=0.5

Which of the following is most likely the next step in the series?

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An economist conducts a nationwide survey to study the financial perceptions of US adults. Specifically, he asks a random sample of 1,000 US adults: “Financially, are you doing OK or are you struggling to get by?” The results of the survey show that 829 of the 1,000 participants said they are doing OK.

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a. Solve for x in the
diagram

help asap, i will mark brainliest!

A. X = -6 and X = -5.5
B. x = -0.5 and x = -5
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An underground aquifer near Seiling, Oklahoma, sits on an impermeable layer of limestone. West of Seiling the limestone layer is thought to slope downward in a straight line. In order to map the limestone layer, hydrologists started at Seiling heading west and drilled sample wells. Two miles west of Seiling the limestone layer was found at a depth of 220 feet. Three miles west of Seiling the limestone layer was found at a depth of 270 feet
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Dave has $70 saved and earns $20
each month in allowance. Terri has
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Seven times a certain number plus the number is equal to 88. Find the number.

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A new animal hospital is planning to purchase a total of 36 cages for dogs, cats, and
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Evaluate the following: a. 4|−8| b. 2|−3| + 4(7) c. 8|−2| − 6 d. 5|−4| + 2|−6|

23:
-
Determine the x- and y- intercepts for the graph defined by the given equation.
y = 7x + 3
a. X-intercept is (3,0)
CH
x-intercept is 0.-
y-intercept is 0,-
y-intercept is (3,0)
b.
d. x-intercept is (3, 0)
x-intercept is
0
y-intercept is
10
y-intercept is (0,3)
Please select the best answer from the choices provided
А
ОВ

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