Surds. I asked my math teacher when I'd use them, she said if I became a maths teacher i'd use them...I presume, to teach other people surds incase they become maths teachers and need to teach other people surds incase they become maths teachers...
Now, he's teaching aronautic engineering and she's teaching geography. What do they have in common. You guessed it, TRIANGLES. South africa is a huge triangle. And I won't point out the hundreds of triangles on his board.