oforjide:
17 in between 7 and 11,i disagree with u, what (r) need to reshape the folder is an odd number and 9 falls in that position so the correct answer is 9.

Regina Daniel Advocate
How far na?

What are Prime Numbers?
Prime numbers are numbers greater than 1 that can not be formed with the multiplication of two smaller numbers. 1,2,3,5,7,11.....etc.
My answer is r=11ans.

Nigeria youths are really lazy. Always want to make money forgetting education which is the bedrock of success.
...Chiefo....

17?

Vendee:

Viewing the topic and studying the shape are enough to show seriousness especially when you are not with pen and paper at that moment.

Keep telling yourself that.

oforjide:
17 in between 7 and 11,i disagree with u, what (r) need to reshape the folder is an odd number and 9 falls in that position so the correct answer is 9.

9 is NOT a prime no. cuz it's divisible by 3.

I only know my access bank account number , pls tell me what prime number means after school.

Karleb:
Although I do not understand the question but 9 is not a prime number.

hu?

dacool1:
Answer is 7
Since the chords are enclosed to form a cyclic polygon and are of lengths 1,2,3,5,7,11,13
Angle at center =360
Ratio of angles =1:2:3:5:7:11:13
Sum of ratio =42
Working with chord 7
Angle subtended by chord 7 =7/42 *360
ANGLE = 60
Length of chord =2rsin®/2
7=2rsin30
R=7/2sin30
R=7

Wow!!!
I never thought of this.
You studied mathematics?

RonKenoly:

Keep telling yourself that.

Some people just want to study on Nairaland, how about that? I studied the shape and so the answer, that's all I want. You could call that lazy.

rockcitie:


9 is NOT a prime no. cuz it's divisible by 3.

define a prime no.

Vendee:

Some people just want to study on Nairaland, how about that? I studied the shape and so the answer, that's all I want. You could call that lazy.

You believe others were lazy for not answering the question, when you are also guilty of same.

What if others want to only study as well, ar they lazy?

perpeling22:
define a prime no.

A prime no. is a no. that is only divisible by 1 and itself. E.g. 5,7,3,11

perpeling22:
define a prime no.

A prime no. is a no. that is only divisible by 1 and itself. E.g. 5,7,3,11

Radii =12

The answer cannot be a prime number, using Pythagoras theorem, it's a²+b² = c²
13/2 = 6.5 which is b
a²+6.5² = 11²
11² - 6.5² = a²
121 - 42.25 = a²
78.75 = a²
a = 9
The answer is 9

rockcitie:


A prime no. is a no. that is only divisible by 1 and itself. E.g. 5,7,3,11

thanks very much.

Martinez

Harbioye:



Wow!!!
I never thought of this.
You studied mathematics?

Nope, accounting actually, I guess I was just lucky with this one

perpeling22:
thanks very much.

You're welcome

dacool1:
Answer is 7
Since the chords are enclosed to form a cyclic polygon and are of lengths 1,2,3,5,7,11,13
Angle at center =360
Ratio of angles =1:2:3:5:7:11:13
Sum of ratio =42
Working with chord 7
Angle subtended by chord 7 =7/42 *360
ANGLE = 60
Length of chord =2rsin®/2
7=2rsin30
R=7/2sin30
R=7

it didn't work, angle of a chord isn't linearly proportional to the length. Try and calculate angle of remaining chords, the total was more than 360

perpeling22:
hu?

9 is odd not prime.
odd numbers are numbers that give a remainder when divided by 2.
prime numbers are numbers with 2 factors I.e. 1 and itself.

9 has 3 factors: 1, 3 and 9.

R~=7.78

Its 8.5 or 9. No need for calculation because its in A circle with a definite dimension.

What a puzzle

Too much thinking

RonKenoly:

You believe others were lazy for not answering the question, when you are also guilty of same.

What if others want to only study as well, ar they lazy?

Oh, I see. Please read my first post here again.
Happy night rest!

Mrshape:
I am having difficulty posting shape with my other account thus I created this as a supplement fellow friends of shape.
Solve

The answer is 9

Funaki:


it didn't work, angle of a chord isn't linearly proportional to the length. Try and calculate angle of remaining chords, the total was more than 360

The reason for the deviation is approximation. That was why I chose the chord which eliminated the approximation error.

Humanaces:
9 ....it so easy

pick your book again

dacool1:

The reason for the deviation is approximation. That was why I chose the chord which eliminated the approximation error.

when I used cosine rule with r=7. I got total angle around 390. that's too much

r=7

r=17