SummaryA Castle Idea from Bagua/Trigram Figure. for more about bagua ,pls click the link below. https://en.wikipedia.org/wiki/BaguaInstructionsWhen I saw the Thingiversity Math Challenge: Build A Castle challenge,I got an idea to build one with Binary* value. But to how make it in to a castle without putting any number? " Bagua* " is enlighten me. (to know more about Bagua can check here https://en.wikipedia.org/wiki/Bagua) some Idea is come out in my mind with "Bagua" and Trigram Figure But this is my 1st 3d model that create with Sketchup Make. Only basic tools I used. Mainly is Push/Pull tools. I try to make window door and more other detail. There is still a long way to go。 In mathematics and digital electronics, a binary number is a number expressed in the binary numeral system. （more about binary you can read at https://en.wikipedia.org/wiki/Binary_number）