How can u tell which side if the heart is the anterior ir losterior side?

From the anterior you can see the anterior intraventricular and coronary sulci. From the posterior you can see the posterior intraventricular sulcus and the posterior coronary sulcus. It's easiest to spot the sulci on the posterior side. The posterior intraventricular sulcus separates the left ventricle from the right ventricle. The coronary sulcus separates the left and right atria.