Okay kiddo, let's talk about a planar lamina!
So imagine you have a piece of paper, like the ones you draw pictures on. This piece of paper is flat and doesn't have any bumps or curves on it. We call this kind of flat surface "planar."
Now, let's say you want to cut out a shape from that paper. Maybe you want a square, or a circle, or a triangle. When you cut out that shape, you have created a planar lamina!
A planar lamina is just a fancy way of saying a flat shape that you can hold in your hand. It's still flat, just like the paper it came from, but now it has a specific shape that makes it different from other planar lamination.
So remember, if you ever cut out a shape from paper or cardboard or anything else flat, you've made a planar lamina! Pretty cool, right?