Check my study guide answers? I don't understand #4...Will fan and give medal!! Attached below as a photo

Question

nightmarenight · Answer

attachment

solomonzelman · Answer

okay, $\normalsize\color{royalblue}{     \rm \text{#}~4   }$.

you are given that the radius is 6ft.

The formula for the area of a circle, is:  $\Large\color{royalblue}{     \rm A= \pi r^2 }$.

solomonzelman · Answer

So for number 4, plug in 6 for r, and tell me what your area will be (in terms of $\large\color{ro blue}{     \pi   }$).

nightmarenight · Answer

113? @SolomonZelman

solomonzelman · Answer

you are not plugging anything for $\large\color{royalblue}{     \pi   }$.

nightmarenight · Answer

6^2 x 3.14 right?

solomonzelman · Answer

Horrible day, keep disconnecting. I wanted to also confirm for all problems accept number 4.

solomonzelman · Answer

Like if my radius was 25, then I would do this:
$\large\color{slate}{  A=\pi r^2     }$
plug in 25 for r,
$\large\color{slate}{  A=\pi (25)^2     }$
$\large\color{slate}{  A=625\pi      }$

solomonzelman · Answer

See how my answer is in terms of $\large\color{slate}{  \pi     }$ ?
Do the same for yours but with the radius of 6 ft, and tell me what I get.

solomonzelman · Answer

(I mean what you get)

nightmarenight · Answer

Oh, 36π ?

nightmarenight · Answer

That was suppose to be a pi sign @SolomonZelman

solomonzelman · Answer

yes I see.

solomonzelman · Answer

you can use this for $\large\color{slate}{ \pi  }$

(copy paste this code)
`$\large\color{slate}{ \pi  }$`

solomonzelman · Answer

and yes, $\large\color{slate}{ 36\pi  }$ is correct.

nightmarenight · Answer

Ohhhh! I kept multiplying 36 x 3.14....Thank you!

solomonzelman · Answer

I know normally I would use ALT codes for most of the things, but these weird question marks are messing it all up.

and yes, it is sometimes that you need to use $\large\color{slate}{ \pi  }$....

( $\large\color{slate}{ \pi  }$ is the proportional relationship between circle's Circumference and the diameter. Not sure who invented this, but it is a "Euler number" you will see Euler numbers more in the future)

solomonzelman · Answer

remember that 3.14 is only an approximation, it is not an exact value of $\large\color{slate}{ \pi  }$. So to be percise when finding the area, you might sometimes want to leave $\large\color{slate}{ \pi  }$ as it is.
(Or in engineering, approximate at the end of calculation only)

solomonzelman · Answer

You welcome....

nightmarenight · Answer

Are the rest of my questions correct? o: @SolomonZelman

solomonzelman · Answer

yes.