Keep checkbox checked or unchecked based on some value

I am using checkbox

<input type="checkbox" value="{{areaFilter.area_name | lowercase}}" ng-checked="true" />

I want to keep checkbox already checked or unchecked while page loading depend on some value (selectedArea) : Like

if(selectedArea.indexOf(areaFilter.area_name) > -1)

Then

ng-clicked="true"

else

ng-clicked="false"

How can I do this in HTML page.

Please guide.