You can see visible light waves diffract through curtains. Look out at a
street lamp. The light will spread left and right and up and down. This
occurs because the light diffracts when it goes through the weave of
Sound waves diffract when they pass through a door. The sound spreads and fills the room on the other side of the door.
Radio waves (especially AM) diffract when they encounter buildings. The
radio waves bend around the building and the reception is still good on
the opposite side. There is no "shadow" of the radio wave.
Hope this helps u.....................^_^