Problem 45408. Yoonir - 03

Created by Asif Newaz

Solve Later

{"relationships":[{"relationshipType":"http://schemas.mathworks.com/matlab/code/2013/relationships/document","relationshipId":"rId1","target":"/matlab/document.xml"},{"relationshipType":"http://schemas.mathworks.com/matlab/code/2013/relationships/output","relationshipId":"rId2","target":"/matlab/output.xml"}],"parts":[{"partUri":"/matlab/document.xml","relationship":[],"contentType":"application/vnd.mathworks.matlab.code.document+xml","content":"<?xml version=\"1.0\" encoding=\"UTF-8\"?><w:document xmlns:w=\"http://schemas.openxmlformats.org/wordprocessingml/2006/main\"><w:body><w:p><w:pPr><w:pStyle w:val=\"text\"/></w:pPr><w:r><w:t>Find the area of a seven-pointed star inscribed in a circle of radius r.</w:t></w:r></w:p></w:body></w:document>"},{"partUri":"/matlab/output.xml","contentType":"text/xml","content":"<?xml version=\"1.0\" encoding=\"UTF-8\" standalone=\"no\" ?><embeddedOutputs><metaData><evaluationState>manual</evaluationState><layoutState>code</layoutState><outputStatus>ready</outputStatus></metaData><outputArray type=\"array\"/><regionArray type=\"array\"/></embeddedOutputs>"}]}

Solve

Solution Stats

34 Solutions
16 Solvers

Last Solution submitted on Dec 30, 2020

Last 200 Solutions

Problem Comments

6 Comments

6 Comments

Show 3 older comments

William on 5 Apr 2020

Hi Asif,
I'm puzzled. Now 2 people have submitted solutions that agree with the test suite, but the test suite seems wrong to me! Looking at all 3 'yoonir' problems for a radius of 10 units:
Program Points test_suite my_calc
yoonir_02 5 112.27 112.26
yoonir_04 6 173.20 173.21
yoonir_06 7 108.34 210.17
How would it be possible that in going from a 6 pointed star to a 7 pointed star, the area drops from 173.2 to 108.3?

Asif Newaz on 7 Apr 2020

hello William,

in the figure, the available area inside the polygon of a 7-pointed star has actually decreased compared to 6-pointed star .isn't it?

Asif Newaz on 7 Apr 2020

https://i.pinimg.com/474x/27/ce/d6/27ced6447ff40b38ae3d5784b30936a9.jpg

William on 7 Apr 2020

Gosh, that seems to be right! I thought my solution was good for all N, but I can see from that figure that it's not. Thanks for the tip.

William on 8 Apr 2020

Asif,
I have discovered something! While there is just one way to draw a five-pointed star or a six-pointed star, there are actually two ways to draw a seven-pointed star. One of them has an area much larger than the other.

Asif Newaz on 9 Apr 2020

yes i saw that later on utube..didn't know that before

Solution Comments

Solution 2185339

1 Comment

1 Comment

Asif Newaz on 2 Apr 2020

It was actually unintentional. I originally intended to submit only the 1st problem of yoonir(which is a 5 pointed star) but then it suddenly came to mind what about a 6/7 pointed star. Tried to calculate one by one.

a generalized problem of an n-pointed star would have been gd.

Problem Recent Solvers16

Problem Tags

area geometry

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Problem 45408. Yoonir - 03

Solution Stats

Last 200 Solutions

Problem Comments

Solution Comments

Problem Recent Solvers16

Suggested Problems

More from this Author149

Problem Tags

Community Treasure Hunt

Problem 45408. Yoonir - 03

Solution Stats

Last 200 Solutions

Problem Comments

Solution Comments

Problem Recent Solvers16

Suggested Problems

More from this Author149

Problem Tags

Community Treasure Hunt

Players