Trap Rule for sin(x) 
Use the trapezoidal rule with $N=6$ to approximate the arc length of the curve $f(x) = \sin(x)$ from $x=0$ to $x=\pi$.

So I found that $\Delta x = \frac{\pi}{6}$ which means that my interval points are $0,\frac{\pi}{3}, \frac{\pi}{2}, \frac{2\pi}{3}, \frac{5\pi}{6}$ and $\pi$.
Is that right?
And then after that I just use the trap rule forumula computing the value of $\sin$ of all my interval points.
Is my thinking correct?

Well your going after arc length here so you either wanna switch sin(x) to sqrt(1 + cos(x)^2) 
Since dLength^2 = dx^2 + dy^2
Or:
You can keep in mind it is the length of the top sides of your trapezoids, Not their area, that you want to sum up.
Besides that you should be good to go.
