trouble facing with changing cell size to a desired resolution

[shamimaferdousi]

please help me.when I create a polygon (the cell size is given 0.0031 automatically) and rasterize it, the cell size remains 0.0031, in angular degree. I projected it to convert it into meter, in the hope that the cell size will change. I tried to change it even during rasterize operation.the results were not fruitful. it just came as a block of singular color sometimes or sometimes doesn't show the layer even.On the other hand, all other raster variables have cell size 12.5. And i need to convert this polygon to raster to a cell size of 12.5. How can I do this??? Is there any way?

thank you

[DanPatterson_Retired]

When you project it using Project Raster, to a planar coordinate system, specify the cell size there.  You can do this in several ways, but setting in the tool.  It says it is an optional parameter. 

It is only optional if you don't care or couldn't be bothered to specify a useful one... read about how it works as well

[XanderBakker]

I would recommend you to Project—Help | ArcGIS Desktop the polygons first to a projected coordinate system and use Setting geoprocessing environments—Help | ArcGIS Desktop in which you specify the Cell Size (Environment setting)—Help | ArcGIS Desktop prior to the Polygon to Raster—Help | ArcGIS Desktop conversion.