₦airaland Forum

Jaeis:
My major issue is that assumptions were made to arrive at a figure for the diameter of the shaded portion.

Please point out the assumption

Martinez39s:
In Maths, you don't just make assumptions without proof and present present them as solutions. Even by mere intuitive geometric consideration, |OF| cannot equal |ON|. If did, circle centred at O would touch F. |ON| is the radius of the circle centred at O, how then |OF|, which is clearly bigger that the radius of the circle centred at O, equal to |ON|?


MrShape.

Thank you o

Jaeis:
The only part I don't understand is why the height of the triangle should be 14. Bro na lie

Did u say the height of the triangle is 14?
Check again.
I never said that o

Kylekent59:
394.24cm²

Nice you used 22/7 as pie?

Jaeis:
According to Rezos017 OF = 14 fire!!!! Lies. How?

I don't know why he made that assumption I am still try to learn from him. Let him come up with a proof, we might gain one or two things from it

Jaeis:
Pure magic (assumptions). That triangle is filled with imaginary dimensions.


The top part of the triangle is my issue. I understand the dimensions of the base and part of the slant height

Distance from center of a circle to any part of the circumference is a radius.
That was why I placed R as the top dimension in the shaded portion.

Next because the radius of the bug circle is the distance of the center of the circle to the circumference,

Take a distance from the center of the big circle vertically upward to the circumference, you find out that it is made up of R and H
That's why
R+H=28
then H=28-R.

Ii font known if that was the issue Sir

Jaeis:
Pure magic (assumptions). That triangle is filled with imaginary dimensions

Smile there is a geometric reason for each line I used imaginary line to show those lines are not part of the original diagram

Follow Mr shape

Rezos017:
The absence of proof is not necessarily a proof of absence. What is ur own evidence dat OF is not equal to ON? Should I just accept it because Mr Shape said so?

Smile. No you should not believe I because I said it.

But in geometry we do not make any assumption without a proof.

If it can't be proved diagrammatic/ and algebraically,/ and coordinately
It is inaccurate.
There most be a proof.
Martinez39s can you help me out here please I am short of words

Jaeis:
How did you all get the diameter or radius of the shaded portion

Check my solution in the first comment
Then ask question on specific pleases you don't get, I will be glad to help

agatoid:
173.25cm²

No sir rather show workings to prove your solution please

Rezos017:
what 14? Can u specify how using d 14 is incorrect?

Yes.
Because no proof that |OF|=|ON|

Rezos017:
Overlook the poor sketch...not drawn to scale anyway.

Were you got it wrong is the 14 you made use of.
That h was unknown

stanisbaratheon:
Okay.

I wish I can do the construction to verify that.

Well, What I did was to assume a line drawn from point "F" upward to the circumference of the main semicircle, and then deducted the radius of the small semicircle from the Radius of the main semicircle to get the diameter of the shaded portion.

Alright check my basic solution I have posted it

Rezos017:
mmmm...looks like its high time u changed ur moniker from 'Mr Shape' to something else. How about 'Mr CashPrize'?

Lol

stanisbaratheon:
hmmmm.....

Chord to which?? The shaded circle or the small semicircle??

It us a chord of the shaded circle

Rezos017:
Ok your Highness. A diagram will be posted as you ordered. And what's the reward for all d mental stress? Dont tell me its jus to keep one's mind off corona virus wahala

If you get it j will give you more shapes to solve as a reward.
What else does Mr shape has to offer

stanisbaratheon:
How so??

I think what I did was correct. But if you still think otherwise, why am I wrong?

The line joining the the shaded circle to the top of the smallest circle is a chord not a diameter.
The diameter did not stop at the to of the circle thus
Diameter of shaded circle>28-7
Clear?

Rezos017:
Using some construction and a bit of pythagoras stuff, i got 8.65cm as the radius of d shaded circle. The area of the shaded circle would be 3.142 * 8.65 * 8.65 = 235.09cm sq. to 2 d.p

Show diagram

dazzlingd:
I got 346.4 using pie as 3.412

Show workings

stanisbaratheon:
Diameter AB= 56cm
Radius of AB=56/2=28cm
Diameter of AE=EF=FG=GB=56/4=14cm
Radius of AE=EF=FG=GB=14/2=7cm

Diameter of shaded portion=28-7=21cm

Area of shaded portion=(πD^2)/4=(π×21^2)/4

Area=(3.14159×21^2)/4=1385.44/4 =346.36sq.cm

28-7=21 has no proof

stanisbaratheon:
1385.44sq.cm

Show workkngs

TalabiAudu:
Let me refresh first

Waiting

Na story

You people will survive this hard times my prays are with you

Hmmm this man is too convinced of its allegation

This would have been helpful to me because at this time I need zoom more than ever before and it consumes data

Good better than money,
But they might still sell it

okrikaboi:
I gave up on maths since 2018 and I promised never to return and I have not regretted my decision.

Until you start writing amplitude test for big employment and contract

jackpot:
Hello house,

Can you kindly help to find x from the diagram?

X is 20°

jackpot:
Hello house,

Can you kindly help to find x from the diagram?

I will do it tomorrow I am feeling sleepy now.

Martinez39s:
I know I am correct. I have even plotted the graphs of the circles using my results.
#CoordinateGeometry

Lol You are correct,
But I will also appreciate basic solution