Question

Work out the area of this circle.

Take pi to be 3.142 and give your answer in 2 decimal places.

Answer 1

Hi student, let me help you out! :)

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We are asked to find the area of this circle.

`\triangle~\fbox{\bf{KEY:}}`

→
`\bf{Area_(circle)=\pi r^(2)}`

Notice that we are asked to use 3.142 for
`\pi` (pi).

The radius isn't given to us; what we have instead is...the diameter.

To find the radius, we divide the diameter by 2.

`\ddot\bigstar` Remember this...

`\fbox{\bf{To\;find\;the\;radius,\;we\;divide\;the\;diameter\;by\;2}}`

Thus, the radius is

`\bf{9/2=4.5}`

Now substitute the values (3.142 for pi and 4.5 for r):

`\bf{A=3.142*4.5^(2) }`

Simplifying,

`\bf{A=3.142*20.25}`

Simplifying,

`\bf{A=63.6255\:m}`

Rounding to 2 decimal places (D.P.):

`\bf{A=63.63\:m}`

Hope it helps you out! :D

Ask in comments if any queries arise.

~Just a smiley person helping fellow students :)

Answer 2

Answer: 63.63 m²

Step-by-step explanation:

Area of circle:

• π(radius)²

Here given:

radius: (diameter/2) = (9/2) = 4.5 m

π should be taken as 3.142

So area of circle:

• 3.142(4.5)² = 63.6255 ≈ 63.63 (rounded to two decimal place)