# I am attempting to make a model of an iris diaphragm however I do not know how to rotate polygon objects

**URL:** <https://cl.desmos.com/t/i-am-attempting-to-make-a-model-of-an-iris-diaphragm-however-i-do-not-know-how-to-rotate-polygon-objects/3976>\
**Category:** Questions\
**Created:** [January 19, 2022, 9:26pm UTC](https://cl.desmos.com/t/i-am-attempting-to-make-a-model-of-an-iris-diaphragm-however-i-do-not-know-how-to-rotate-polygon-objects/3976 "2022-01-19T21:26:08Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![Not\_A\_Chair](https://yyz1.discourse-cdn.com/flex031/user_avatar/cl.desmos.com/not_a_chair/32/3292_2.png) [@Not\_A\_Chair](https://cl.desmos.com/u/Not_A_Chair)\
**Post date:** [January 19, 2022, 9:26pm UTC](https://cl.desmos.com/t/i-am-attempting-to-make-a-model-of-an-iris-diaphragm-however-i-do-not-know-how-to-rotate-polygon-objects/3976/1 "2022-01-19T21:26:08Z")

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Here is a link to the graph: [Polar coordinates](https://www.desmos.com/calculator/qufcu1askt)  
I would appreciate help.

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**Author:** ![cwinske](https://yyz1.discourse-cdn.com/flex031/user_avatar/cl.desmos.com/cwinske/32/3106_2.png) [@cwinske](https://cl.desmos.com/u/cwinske)\
**Post date:** [January 20, 2022, 1:14am UTC](https://cl.desmos.com/t/i-am-attempting-to-make-a-model-of-an-iris-diaphragm-however-i-do-not-know-how-to-rotate-polygon-objects/3976/2 "2022-01-20T01:14:45Z")

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Looks like you have the framework needed! Try adjusting the `c` variable to have minimum and maximum values of 0 and 2pi, respectively. Some other adjusting will be needed to fix a rogue triangle, but moving the `c` slider will rotate the triangles!

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**Author:** ![Not\_A\_Chair](https://yyz1.discourse-cdn.com/flex031/user_avatar/cl.desmos.com/not_a_chair/32/3292_2.png) [@Not\_A\_Chair](https://cl.desmos.com/u/Not_A_Chair)\
**Post date:** [January 24, 2022, 8:52pm UTC](https://cl.desmos.com/t/i-am-attempting-to-make-a-model-of-an-iris-diaphragm-however-i-do-not-know-how-to-rotate-polygon-objects/3976/3 "2022-01-24T20:52:43Z")

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But how do I move the center of rotation so that it is in the center of each triangle?

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<div class="post-metadata">

**Author:** ![cwinske](https://yyz1.discourse-cdn.com/flex031/user_avatar/cl.desmos.com/cwinske/32/3106_2.png) [@cwinske](https://cl.desmos.com/u/cwinske)\
**Post date:** [January 25, 2022, 1:18am UTC](https://cl.desmos.com/t/i-am-attempting-to-make-a-model-of-an-iris-diaphragm-however-i-do-not-know-how-to-rotate-polygon-objects/3976/4 "2022-01-25T01:18:27Z")

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See if this helps. You’ll just need to define the center of your polygon(s) and then you can use this idea. Let me know if you need any clarification on anything! [Graphing Calculator](https://www.desmos.com/calculator/zqxl00zbgg)