# How to place markers on the outline of a circle in google maps?

I have the center of a circle and it's radius and I need to place variable amount of markers on the outline/stroke of the circle. The distance between this markers should kept same, so if I have 8 markers to put on the orbit, each of them has 45 degree space (360 / 8) and also it should not be hard-coded as the number of markers is variable.

I wanted to know what is the right way for calculating the Geo-coordinates of each marker?

here you can see an example, the outer marker should move on, however I can't calculate the proper LatLng values.

I finally came up with this formula:

``````var dg = 90;
var lat = Math.sin(dg * Math.PI / 180) * r + center_geo_lat;
var lng = Math.cos(dg * Math.PI / 180) * r + center_geo_lng;
``````

If you look at snapshots you can see that markers at 0 and 180 degree has placed quite fine, but it seems there is something wrong with other markers. It's gonna works fine for me, because I don't need such a perfect accuracy, however I'm wondering what's cause the problem?

• Please see this Question and Answers for the info on the stretch in a North/South direction gis.stackexchange.com/questions/6822/…
– Mapperz
Commented Oct 26, 2012 at 13:10
• I merged your questions since the second one was following up on your first attempt at solving the question posed in the first one. Commented Oct 26, 2012 at 13:32
• @Mahdi What is radius' unit in this question ... meters, kms, miles etc ? Commented Nov 27, 2017 at 19:14
• @HarisurRehman Sorry I can't really remember. I guess that should be kilometres -- same as earth's radius unit, in this example, but I might be wrong. Commented Nov 28, 2017 at 21:02
• No its not kilometres, just tested. i.imgur.com/dKdiNp4.png Commented Nov 29, 2017 at 3:58