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3 years ago

Find the area of a circle with a circumference of 31.4 units. help me please

Mathematics

1 answer:

hram777 [196]3 years ago

4 0

Answer:

Area = 78.5

Step-by-step explanation:

31.4 = 2 x pi X r

r = 31.4/(2xpi) = 31.4(2 x 3.14) = 5

Area = pi x r^2 = 3.14 X 5^2 =3.14 x 25 = 78.5 units^2

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jenyasd209 [6]

Answer:

Step-by-step explanation:

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3 years ago

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nexus9112 [7]

Answer:

point-slope:x-y+3

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3 years ago

what is the circumference of a circle that has a radius of 8 units use 3.14 (pie) and round to the nearest hundredth

SashulF [63]

Remember that the formula for the circumference, $C$ , of a circle is:

$C = d \pi$

In this case, we are not given the diameter. However, remember that the diameter is equivalent to two times the radius of a circle. Thus,

$d = 2 \cdot 8 = 16$ ,

and we can say the circumference of our circle is:

$C = 16 \cdot 3.14 = 50.24 \,\textrm{units}$

The circumference of our circle is 50.24 units.

Also, a little side note not relating to the question:

Remember that $\pi$ is spelled as "pi" not "pie." Pie is a dessert, while pi is a mathematical constant.

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3 years ago

What's 8n-(2n-3)=12?

Alborosie

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8n-2n= 12+3
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Hope this helps :)

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3 years ago

An isosceles triangle has a perimeter of 18 cm. Find a function that models its area A in terms of the length of its base b.

IgorLugansk [536]

So.... notice the picture below

now, we know what the "height" or "altitude" is
now, we also know the perimeter is 18cm

so, k + k + b = 18
or 2k + b = 18
thus $\bf k=\cfrac{18-b}{2}$

so... one can say that $\bf \textit{area of a triangle}=A=\cfrac{1}{2}bh\qquad 
\begin{cases}
b=b
\\\\
h=\sqrt{k^2-\left( \frac{b}{2} \right)^2}
\\\\
h=\sqrt{k^2-\frac{b^2}{4}}\\
--------------\\
k=\frac{18-b}{2}\qquad thus\\
--------------\\
h=\sqrt{\left( \frac{18-b}{2} \right)^2-\frac{b^2}{4}}
\end{cases}\\\\
-----------------------------\\\\
A=\cfrac{1}{2}\cdot b\cdot \sqrt{\left( \frac{18-b}{2} \right)^2-\frac{b^2}{4}}$

and you can simplify it if you wish.. not sure you have to

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3 years ago