An angled effect is actually how the firework is physically set up; what it means is that the tubes of the fireworks are pointed at an angle in different directions and positions rather then having all of the shots pointed straight up like with a standard multi-shot cake.
Out-of-Home advertising structures are built for maximum visibility to vehicles approaching them. They are classified as angled when one end is set back more than 6' from the other end of the structure as measured along the line of travel.