Form Intersection Please help me level up

[neopatogen]

Hi i would like to clear some confusion if i made some error will doing Form intersection thank you

Here 2 version the second one is suppose to be the correction

Please feel free to explain and correct my misunderstanding of some of the The corrected version looks

The corrected version looks good!
A good way to check the intersections that you doubt about is to recteate your simple forms in Sketchup. Free version is enough for that purpose.There's an option there to show hidden lines (like if you were "drawing through"). Check it out if you haven't already, it's quite intuitive for beginners in 3d. I used this method to check my Drawabox intersection excercise. Btw where is your excercise from? Some art course?