The FireTtriangle. Most people have heard of the fire triangle: heat, fuel, and oxidizer. When these three components come together in the proper proportions, a fireâthe rapid chemical reaction of fuel with oxygen, resulting in the release of heat and light energyâis bound to occur.
Answer by Hank W. The average length of the northern hemisphere summer, calculated as the average time from the June solstice until the September equinox, is about 93 days and 15Â½ hours. The average length of the southern hemisphere summer, calculated as the average time from the December solstice until the March equinox, is about 89 days.
The year is divided into the four seasons based on the two equinoxes and the two solstices. The summer and winter solstices, which typically land around June 21 and December 22, mark the shortest and the longest days of the year. The autumnal and vernal equinoxes, which fall around September 23 and March 21, mark the points in the year when the day and the night are of equal lengths.