The area enclosed by the curves $$y = \sin x + \cos x$$ and $$y = |\cos x - \sin x|$$ over the interval $$\left[ {0,{\pi \over 2}} \right]$$ is

The area of one curvilinear triangle formed by curves y = sin x, y = cos x and X-axis, is

Circle centered at origin and having radius $$\pi$$ units is divided by the curve y = sin x in two parts. Then area of upper parts equals to