Turtle Spiral Generator

Imagine there's a turtle drawing the line spirally. See the following examples directly.

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- height = 5
- beginning_length = 100
- decreasing_step = 0.5
- angle = 89
- ending_length = 5
- line_width = 1

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- height = 5
- beginning_length = 100
- decreasing_step = 0.5
- angle = 73
- ending_length = 5
- line_width = 1

----
- height = 5
- beginning_length = 100
- decreasing_step = 2
- angle = 145
- ending_length = 5
- line_width = 1

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I use this as a based to create [Spiral Characters](https://www.thingiverse.com/thing:1404251)：

[![Spir