# How to draw circle with even number diameter (for example, 100)

**URL:** <https://forum.opencv.org/t/how-to-draw-circle-with-even-number-diameter-for-example-100/1031>\
**Category:** Uncategorized\
**Tags:** imgproc\
**Created:** [January 21, 2021, 3:56pm UTC](https://forum.opencv.org/t/how-to-draw-circle-with-even-number-diameter-for-example-100/1031 "2021-01-21T15:56:47Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![mgukov](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.opencv.org/mgukov/32/679_2.png) [@mgukov](https://forum.opencv.org/u/mgukov)\
**Post date:** [January 21, 2021, 3:56pm UTC](https://forum.opencv.org/t/how-to-draw-circle-with-even-number-diameter-for-example-100/1031/1 "2021-01-21T15:56:47Z")

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I need draw circle with even number diameter (for example, 100 px).  
If use cv::circle() or cv::ellipse() diameter always is odd number ;

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<div class="post-metadata">

**Author:** ![kbarni](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.opencv.org/kbarni/32/26_2.png) [@kbarni](https://forum.opencv.org/u/kbarni)\
**Post date:** [January 21, 2021, 4:53pm UTC](https://forum.opencv.org/t/how-to-draw-circle-with-even-number-diameter-for-example-100/1031/2 "2021-01-21T16:53:39Z")

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In `ellipse()` function you can define the bounding box of the ellipse (a `RotatedRect`), which can have any size (even real numbers).

For example a circle with diameter=100:

```
ellipse(image, RotatedRect(Point2f(100,100), Point2f(100,200), Point2f(200,200)), Scalar(0,0,255);
```