In order to find the volume of an irregular shape, your going to need a graduated cylinder, and water. The first step is to fill the graduated cylinder up to an amount so that when you drop the object the water won't spill. Let's just go with 30ml. After you filled the graduated cylinder with water, now you are going to gently drop the object in the graduated cylinder. Before you even drop the object make sure you got the amount of water level when you first started. After you drop the object you measure the water level after you dropped the object. The final step is to subtract the the water level before to the water level now. So there you have it!