What is the area of a circle with a diameter of 20 inches if
=3.1415​

$\sf\underline\bold\blue{Information\:given\:in\:the\:question:}$

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$\sf\underline\bold\blue{What\:we\:have\:to\:find?}$

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$\sf\underline\bold\blue{}$

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$\sf\underline\bold\blue{Calculations:}$

Here we have the value of the circle's diameter that is 20inches. So, first we have to calculate the radius of the circle using the formula :

$\mapsto$ $\sf\bold{Radius=}$ $\sf\dfrac{Diameter}{2}$

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$\sf\underline\bold\blue{Calculating\:the\:required\:values:}$

$\mapsto$ $\sf\bold{Radius=}$ $\sf\dfrac{20}{2}$

$\sf{Convert \: to \: the\:lowest\:term(Divide),}$

$\mapsto$ $\sf\underline\bold{Radius=10}$

☆Now we know the value of the radius . So now let's calculate the area of the circle.

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$\sf\bold{Area\:of\:circle:}$ π$\sf{ r \: ^{2} }$

$\sf\bold{Evaluating \: the\:required\:values:}$

$\sf\bold{Area\:of\:circle=3.1415(10)^2}$

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$\sf\bold{Area\:of\:the\:circle=3.1415\times10\times10}$

$\sf\bold{Now,}$

$\sf\bold{Area\:of\:the\:circle:3.1415\times100}$

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$\sf\underline\bold\green{Thus,Area\:of\:the\:circle\: is \: 314.15}$

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54 km / hours

step-by-step explanation:

we need to convert seconds to hours

60 seconds = 1 minutes

60 minutes = 1hour

15 m         60 second   60 minutes

  * *         = 54000 meters/ hour

second     1 minute             1 hour

now we need to convert meters to km

1000 m = 1 km

54000 m       1 km

*   = 54 km / hours

hour               1000m

b. 1.25 hr

step-by-step explanation:

if you have a constant speed of 60 mph, then you have a ratio between 60 mi. to 1 hr. dividing both sides by 60 we get the ratio

1 mi. to

then mult. both sides by 75 we get the ratio

75 mi. to

simplifying we get

75 mi. to

or 1.25 hr.