Question

Help again, will medal

Answer 1

*does not helps*

Answer 2

@mathmate ^

Answer 3

let the radius of the circle be 'r' and area of the shaded region be A

can you use the same formula you used for the earlier problem and write the expression for the area of the shaded region in terms of 'r' and 'A'

Answer 4

So, would it be \[\frac{ 90 }{ 360 } \times 3.14 \times {18}^2\]

Answer 5

Which would equal 254.34

Answer 6

no,
18 is the area of the whole circle
we don't know the radius.
so just leave it as 'r'\[A=\frac{ 90 }{ 360 } \times 3.14 \times {r}^2\]

ok so far?

Answer 7

Ohhhh okay I understand noow

Answer 8

I'm okay so far

Answer 9

we know the the area of the whole circle is 18.

so we have
\[3.14 \times r^2=18\]

followed?

Answer 10

Yes that is right

Answer 11

Where did you get the 18 from

Answer 12

its given in the question,
18 is the area of the WHOLE cirlce

Answer 13

Oh yes yes that is right

Answer 14

Sorry lol

Answer 15

now look at\[A=\frac{ 90 }{ 360 } \times \color{red}{3.14 \times {r}^2}\]

the part marked in red is the same as the formula for the whole circle,
so we can replace that with 18
\[A=\frac{ 90 }{ 360 } \times \color{red}{18}\]

ok?

Answer 16

Ohhhh okay,so since we are already given the area for the entire circle, we just substitute that in? Right?

Answer 17

yep :)
so what do you get as your final answer?

Answer 18

4.5

Answer 19

looks good :)

Answer 20

Baru,Please put in the correct unit.
4.5 square feet.

Answer 21

It is not square feet, its square cm :)

Answer 22

Thank you @baru

Answer 23

@AaronAndyson thanks for pointing that out,
its very important to put in the units,
and it is square feet, since the question gives 18ft^2

Answer 24

No Problem @baru :)

Answer 25

Oh okay , thanks to you both

Answer 26

you're welcome :)