Втрапеции abcd известно, что ad=4, bc=2, а ее площадь равна 60.найдите площадь трапеции bcnm, где mn-средняя линия трапеции abcd.

25 см²

Пошаговое объяснение:

Дано: ABCD - трапеция,  AD=4 см, BC=2 см, S=60 см², МN - средняя линия. Найти S(BCNM).

Решение: МN=(АD+ВС)/2=(2+4)/2=3 см.

Проведем высоту ВН. Найдем ВН из формулы S=MN*BH

60=3ВH;  BH=20 cм.

Найдем S(BCNM)=(ВС+MN)/2 * ВК.

ВК=1/2 ВН, т.к. MN - средняя линия и делит ВН пополам.

ВК=20:2=10 см.

S(BCNM)=(2+3)/2 * 10 = 25 см²

such events (in other words, the cost of the part) are generated from entry fees. Today they range from 1000 to 1500 roubles from the person or from 5,000 to 10,000 rubles with the team. Don't forget about the cost of balls, and travel expenses of the team to the site of the games. For victory in sports competitions in paintball, not counting moral satisfaction, you can get a Cup, medal, diploma or certificate and a cash prize in the amount of from 5000 to 60 000, depending on the initial sum invested.

From the scenario of the game is almost the same rules. Fees for participation by one player range from 1000 to 18 000 rubles. In addition, you need balls, transport, and sometimes accommodation in a hotel complex near the place where fights are held. The reward can also be a commemorative medal, t-shirt with team logo.diploma or Souvenirs that will remind players about their own success.

Abroad, the situation is somewhat different. Aliens-the organizers of the paintball activities usually do not spend money on prizes. For example, one of the largest awards in paintball back in 2007 were the prizes prepared by the company Kingman Group, she is the owner of the brand Spyder. In a series of games in threes "Spyder Cup-2007" the winners got four modern-equipped car Hummer H2. I wonder what these games were characterized by a complete lack of entry fee. However, each participant had to pay for three boxes of balls, each of which costs $ 50. In addition, the winners of the qualifying tournaments have become the owners of receipts 1500, 600 and $ 300 respectively for first, second and third places. Those who finished in second and third place went to checks on the 6000 and 3000 dollars.

Alas, our compatriots can only hope that in the near future, the Russian paintball leaves on absolutely new level, and soon the Russian organizers of the paintball events will be able to declare a much larger prize funds, thus attracting more gamblers.

Люди ,зачастую сами мешают пожарным потушить огонь,потому что не выполняют правил пожарной безопасности,курят в неположенных местах,бросают незагашенные окурки в урны.например,а там бумага,или что-то ещё.Происходит возгорание.А это очень опасно в местах скопления людей.Людей много ,выходы забиты людьми,создается паника,люди бегут,толкают друг друга,падают,образуется давка,а это уже страшно при большом скоплении народа. Пожарные не могут пройти,пробежать,пролезть в конце концов,мешают люди и происходит трагедия.Еще ,если пожар,а все дворы заставлены транспортом,"пожарки"проехать не могут,опять трагедия.А чтобы избежать  трагедий-всем нужно выполнять правила пожарной безопасности.