Arc Length of Smooth, Planar Curve Practice Test

A particle moves with $x(t)=2\sin t$ and $y(t)=2\cos t$ for $0\le t\le\tfrac{\pi}{2}$. What distance is traveled?

A cyclist’s position is $\mathbf r(t)=\langle \cos t,,\sin t\rangle$ for $0\le t\le\pi$. What is the total distance traveled?