如何用角度复选框更改div类

I cant seem to figure out how to change the class with a checkbox value. I can show/hide a class but I need a col-md-6 to change to a col-md-12. I have a map and a chart on the same row. I would like to be able to hide the map and make the chart the full width of the row. And vice versaI cant seem to figure out how to change the cla