The kangaroo is a wild animal which has large, powerful hind legs, a long muscular tail and a small head. There are known over 60 different species of kangaroos and close relatives. Some of them can be two meters tall with weight up to 90 kg. The others are much smaller in size. Kangaroos are unusual and wonderful animals. Kangaroos hop like rabbits to move around quickly. They can jump as far as about three times their own height. They walk on four legs when there is no need to move fast. Kangaroos are called marsupials because they carry their babies in a special bag on their paunches. Kangaroos are herbivore animals, they eat mainly grass and shrubs. They are common in Australia. The kangaroo is one of the most well-known native Australian animals. Although it can also be found in New Guinea kangaroo is the iconic animal of Australia. It is even pictured on the coat of arms for Australia.
Сторона основания m, диагональ основания m√2 Половина диагонали m√2/2, высота и боковое ребро образуют прям-ный тр-ник с катетом m√2/2 и углом против него α/2. tg (α/2) = (m√2/2) / H а) Высота равна H = (m√2/2) / tg (α/2) = m√2*ctg (α/2) / 2 б) Боковое ребро b = (m√2/2) / sin (α/2) в) Апофема (высота боковой грани) L^2 = b^2 - m^2 = (m^2/2) / sin^2 (α/2) - m^2 L = m*√ [1 - 2sin^2 (α/2)] / sin (α/2) = m*√(cos α) / sin (α/2) Угол между боковой гранью и плоскостью основания sin β = H / L = m√2*ctg(α/2) / 2 * sin(α/2) / (m*√(cos α)) = √2*cos(α/2) / (2√(cos α)) г) Двугранный угол при боковом ребре - это не знаю.
Пусть а см - самая коротка сторона. Тогда средняя сторона равна (а + 10) см, а самая длинна - (а + 20) см. В прямоугольном треугольнике самая длинная сторона - гипотенуза, а две другие - катеты. Используя теорему Пифагора, получим уравнение: а² + (а + 10)² = (а + 20)² а² + а² + 20а + 100 = а² + 40а + 400 2а² - а² + 20а - 40а + 100 - 400 = 0 а² - 20а - 300 = 0 По обратной теореме Виета: а1 + а2 = 20 а1•а2 = -300 а1 = 30 а2 = -10 - не уд. условию задачи. Значит, меньший катет равен 30 см. Тогда больший катет равен 30 + 10 = 40 см, а гипотенуза - 50 см. ответ: 50 см.
The kangaroo is a wild animal which has large, powerful hind legs, a long muscular tail and a small head. There are known over 60 different species of kangaroos and close relatives. Some of them can be two meters tall with weight up to 90 kg. The others are much smaller in size. Kangaroos are unusual and wonderful animals. Kangaroos hop like rabbits to move around quickly. They can jump as far as about three times their own height. They walk on four legs when there is no need to move fast. Kangaroos are called marsupials because they carry their babies in a special bag on their paunches. Kangaroos are herbivore animals, they eat mainly grass and shrubs. They are common in Australia. The kangaroo is one of the most well-known native Australian animals. Although it can also be found in New Guinea kangaroo is the iconic animal of Australia. It is even pictured on the coat of arms for Australia.