Question

i need to find the perimeter of the shaded region, but first, how can I find the diameter/radius? is AE=EO?

Answer 1

is the diameter=20

Answer 2

can u draw it out so we may calculate diameter quick ? :)

Answer 3

@ganeshie8
can you help me with the question i posted earlier

Answer 4

why is i^i^i^i^i^i^e= 1 ?

Answer 5

ugh im no better than u... i gave up that problem yesterday itself :'(

Answer 6

wait up..

Answer 7

10pi+40 = perimeter

Answer 8

S-I-M: Really, I don't want to call you "stupidinmath," so would you provide a positive nickname that I could use in stead?

Referring to the drawing you've already shared: construct a right triangle EOF. The base of this triangle, EO, is half of DC, or 5. Its height is 10. What's the hypotenuse of this triangle? Twice that is your diameter.

Answer 9

the file i posted is bettter

Answer 10

P0sitr0n really? c:

Answer 11

mathmale, haha, nah i'm really a stupid in math ..
but yeah, thanks :)

Answer 12

No soap. Reallyl do want another nickname (a positive one) by which I can call you. When you start thinking of yourself as "good in math," you're a lot more likely to be good in math. So, pretty please: a new nickname. Do my comments on your math problem make sense? If so, please calculate the hypotenuse, OD (or DO).

Answer 13

Oh, alright c: mathgenius then? haha. wait let me try

Answer 14

I wouldn't say AE=EO without proof.

Answer 15

So you go right ahead, mathgenius, and see whether you can find the hypotenuse.

Answer 16

125's the hypotenuse

Answer 17

so.. diameter is 20, right?

Answer 18

I see you're using the Pyth. Them. Good. 5^2 + 10^2 = hyp^2 =125.
Now what is the hyp?

Answer 19

\[5^{2}+10^{2}=125=h ^{2}\]
That's great. You've had it right; that was the radius of your semicircle. But then you deleted what you'd typed. Repeat it, please.

Answer 20

If h^2=125, h=+(what?)

Answer 21

√125.. 5√5

Answer 22

Again, perfect, mathgenius! I'd bet that you can now solve the rest of the problem yourself. But I'm sticking around in case you have further questions.

Answer 23

So.. need to multiply it by 2 to get the diameter. so.. diameter's 10√5 right?wrong?

Answer 24

Let's concentrate on being right and pay little or no attention to the possibility of being wrong. To learn, we have to make mistakes.
Yes, you have the diameter correct in 10Sqrt(5).
Let's read the problem statement again, carefully.
What's your understanding of the goal we're aiming to reach?

Answer 25

Or, better phrased, what's our goal in this problem?

Answer 26

Alright, thanks.
finding the peri of shaded region

Answer 27

how will i get that..

Answer 28

Right. I'm assuming that that means the DARK region.
Have you worked with "arc length" before? As in \[s=r*(\theta)\]
??

Answer 29

some parts of it

Answer 30

I guess that's kinda easy that part

Answer 31

OK, mathgenius. We can make this problem a lot less daunting by breaking it up into smaller parts. I ask y ou to focus first on the pie-shaped figure AOD. The curved boundary is called an "arc." We have to determine the length of this arc. Sound familiar?

Answer 32

Yeap, got that:)

Answer 33

using s=r∗(θ) right?

Answer 34

If you've had trigonmetry, it should be relatively easy for you to determine the angle EOD. Think you can do that?
Once you have this central angle in degrees, you must convert it to radians. Or, better yet, obtain the central angle directly in rads. Yes, use s=r(theta). You're a mathgenius.

Answer 35

EOD= 45 degrees?

Answer 36

I'd prefer not to say Yes or No, but rather to ask you to demonstrate how you obtained that.

Answer 37

Oh alright..
E = 90
D= 90/2 = 45
180 - (90 + 45) = 45 = EOD

Answer 38

Have you had trigonometry? If so, does the following sound familiar?\[\tan \theta=\frac{ opp }{ adj }\]

Answer 39

yep, oh right.. wait

Answer 40

Are you familiar with the inverse trig functions, e. g., \[\theta =\tan ^{-1} \frac{ a }{ b}\]

Answer 41

yes, let me find it :))

Answer 42

is 63.43 right? or calculated it wrong?

Answer 43

mathgenius, if you'll look carefully at triangle EOD, you'll see that the side opposite the angle EOC is 10 and the side adjacent to EOD is 5. You could do either of the following:

Write "angle EOD"=\[\tan ^{-1}\frac{ 10 }{ 5}=\tan ^{-1}2,\]

Answer 44

or calculate the actual value (as you have done). Your result is in degrees, so before I respond I'm going to ask you to convert that angle measurement to radians.

Answer 45

1.106?

Answer 46

On my calculator, \[\tan ^{-1}2=1.107 radians, or 63.435 \]degrees. So, you were RIGHT the first time.

Answer 47

You're doing JUST FINE!!

Answer 48

Haha finally:)

Answer 49

Now please find arc length AD. I'd like to see your work, not just the answer.

Answer 50

To find arc length.. just double the angle measurement right?
If <AED =90
so.. Arc AD=180
am i right?

Answer 51

Hold a moment. I'd like to draw a diagram for you.