Digger

Topic:
Angles, Circle
I was watching a construction site, wondering about the odd shape of the digger's main arm. Why would it be bent? Physics and leverage? I asked a physicist and he didn't know. Then I saw a chart http://ilovecharts.tumblr.com/post/75900886203/a-chart-of-digger-reach-sarah and realized it was geometry! Play around with your own design, and compare it to the actual. Would it be possible to make a digger that reaches too far?