In this experiment, I am adding the inradius (let's call it A) and circumradius (let's call it B) of different polygons with equal sides each equal 1 (starting with a square and adding one side each time). The result is A+B=C when side of polygon =1. When comparing the C of one polygon with the C of a polygon with one side more, the difference seems to go smaller, as if approaching a version of π number with 0. before (possibly such as 0.314159265359...). Can anyone confirm it or elaborate on it?
Alexander Lewis
Answered question
2022-10-20
Comparing between regular polygons In this experiment, I am adding the inradius (let's call it A) and circumradius (let's call it B) of different polygons with equal sides each equal 1 (starting with a square and adding one side each time). The result is when side of polygon . When comparing the C of one polygon with the C of a polygon with one side more, the difference seems to go smaller, as if approaching a version of number with 0. before (possibly such as 0.314159265359...). Can anyone confirm it or elaborate on it? I can not go over a polygon with 1000 sides in my computation power, and would like to know what to expect while going towards a polygon with infinity sides. Here are some examples: 4 sided polygon: 5 sided polygon: (Difference of 0.33173498700000015 from previous result) 6 sided polygon: (Difference of 0.3271836359999998 from previous result) 7 sided polygon: (Difference of 0.32461773599999977 from previous result) 8 sided polygon: (Difference of 0.3230266000000004 from previous result) 9 sided polygon: (Difference of 0.32197116999999986 from previous result) 10 sided polygon: (Difference of 0.3212348500000002 from previous result) 11 sided polygon: (Difference of 0.3207006299999997 from previous result) 12 sided polygon: (Difference of 0.32030066 from previous result) 13 sided polygon: (Difference of 0.31999341999999986 from previous result) 14 sided polygon: (Difference of 0.31975226000000045 from previous result) 15 sided polygon: (Difference of 0.3195594899999996 from previous result) ... 999 sided polygon: 1000 sided polygon: (Difference of 0.31830999999999676 from previous result)
Answer & Explanation
relatatt9
Beginner2022-10-21Added 12 answers
Step 1 Consider that the apothem a, circumcircle radius c, and edge of the polygon form a right triangle. That is, we have two legs, one of length 1/2, the other of length a, and a hypotenuse of length c. Then we have:
Step 2 Since the angle is always . We may simplify . Then what you seek to compute is:
This in fact converges to , which is
Emilio Calhoun
Beginner2022-10-22Added 2 answers
Step 1 Let be the value of C for a regular n-gon. I claim that as . Consider the triangle formed by two adjacent vertices and the centre of the polygon. This is an isosceles triangle with apex angle . The inradius is and the circumradius is . As , we have the results and . So as ,