  In this study, we present the observations of extreme-ultraviolet (EUV) waves
associated with an M6.5 flare on 2013 April 11. The event was observed by Solar
Dynamics Observatory (SDO) in different EUV channels. The flare was also
associated with a halo CME and type II radio bursts. We observed both fast and
slow components of the EUV wave. The speed of the fast component, which is
identified as a fast-mode MHD wave, varies in the range from 600 to 640 km s^-1
, whereas the speed of the slow-component is ~140 km s^-1 . We observed an
unusual phenomenon that, as the fast-component EUV wave passes through two
successive magnetic quasi-separatrix layers (QSLs), two stationary wave fronts
are formed locally. We propose that part of the outward-propagating fast-mode
EUV wave is converted into slow-mode magnetohydrodynamic waves, which are
trapped in local magnetic field structures, forming successive stationary
fronts. Along the other direction, the fast-component EUV wave also creates
oscillations in a coronal loop lying ~225 Mm away from the flare site. We have
computed the energy of the EUV wave to be of the order of 10^20 J.
