1- When sunlight hits the earth at an angle, like near the north or south poles, it causes the radiation to be spread out over a larger area, than when the sun hits at a 90 degree angle, like at the equator. Therefore, it is hotter in the areas where the solar radiation is more heavily concentrated.
2- Seasons are when the earth's rotational axis tilts towards or away from the sun. It is tilted at an angle of 23.5 degrees, in relationship to the sun. The part of the earth tilted TOWARDS the sun is the area currently in summer. The area tilted AWAY from the sun is the area in winter.
3-This is basically what I already said. The area that is currently summer, is the part of earth tilted towards the sun. The area where it's winter is the part tilted away. And then obviously, spring and fall, are on the sides that are perpendicular to the sun. Hope that helps! If so, please mark Brainliest!