How To Draw A Heptagram
How to draw a heptagram in one stroke
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As we know we can draw a pentagram in one stroke, then how to draw a heptagram in one stroke?
Here I'd like share some small discoveries.
Now let's draw some heptagrams in one stroke
First, we draw a line, then we draw an isometric line at an angle of 77.1 ° to the first line. Repeat the operation for seveal times, then we will get:
This article we only talk about the occasion that every angels are the same.
If we change the angel to 25.7°
, the graphic became:
Where the two angels came from? We have a formula.
The formula to calculate the angel of polygarm with n angels
If we use π
instead of 180°, use index
indicates the index of next point from current point, then the formule to calculate one angel is:
(π × (n - index * 2) / n
When the index
is 1, it became the formula we used to calculate one angel of a regular polygon.
How many kinds of polygarm with n angels exist?
We can only draw one kind of hexagram, and two kinds of heptagram (the above two).
Actually, how many x-grams we can draw, depends on how many points in the left or right part of the graphic.
We can easily get this:
For odd, the amount of x-grams is (n / 2) - 1
, and for even it's (n / 2) - 2
.
The minimum angle of the polygarm with n angels
The max value of index
which indicates the index of next point from current point, can be calculated by the last two formulas:
For odd, the The max value of index
is n / 2
, and for even it's (n / 2) - 1
.
Then, according to the first formula, we get this:
For odd, the minimume angel is π / n
, and for even it's 2π / n
.
Thanks for visiting
How To Draw A Heptagram
Source: https://itscloudy.gitee.io/blog/2020/01/14/Draw%20a%20heptagram/
Posted by: houckearon1950.blogspot.com
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