Hey Ami, it's not too bad once you get the hang of it. The cubes are pretty easy -- you just have to follow the vertical and horizontal lines on the face of the cube that your secondary cube is intersecting. This will show you where the two cubes meet. For the cylinders, you have to follow the curve of the first cylinder back to the intersecting cylinder, and that will give you your curve where they intersect. Here's the lesson on cylinders if you need some help finding that curve: https://www.proko.com/course-lesson/how-to-draw-cylinders-and-ellipses.