The 90-degree angle would be hotter since this is receiving the most direct sunlight concentrated in a smaller area. In areas at the equator, the angle of incoming rays from the Sun is perpendicular (90 degrees) to the Earth's surface during all days of the year. Such areas experience warm climates throughout the year
The largest state is New York City; with a population above 8.1 million
<span>Sand dunes move because of wind, so to prevent a sand dune from moving you need to either: stop the wind; or stop the sand dune from being able to move. For example, on beaches, sand is stopped from moving by using groynes, which physically stop the sand from being carried any further along the beach
(Copied from my comment, pasting it here because I know on mobile apps you can't see comments, so if anyone searches, etc.)</span>
