Why do I need to know the parts of a suspension bridge?

I just finished my homework, which means I get to blog (yeay!) So anyway, my homework was to find all the freakin parts of a suspension bridge (and no that was not a swear fyi) but who really cares about a stupid suspension bridge? I mean, really? I'm not gonna be like a bridge builder! *sigh* No one cares about this, I don't really give a crap of te many different types of bridges - truss, bam, arch, suspension, I DON'T CARE. I understand that yes, I need this knowledge next year when it comes time to take the state-wide science and engineering tests...it's all very pointless. I AM NOT going to be an engineer, and anyone who is, they can go to engineer school, but seriously, there are some classes which is crap. A lot of things we learn in school just go to waste. Like how to find the volume of a cylinder (I got like a 100 on the test lol but still) *sigh* some things are very, very pointless, such as the parts of a very stupid suspension type bridge.