Объем правильной треугольной призмы равен 48 см в кубе. Диагональ боковой грани наклонена к плоскости основания под углом 60 градусов, а ребро основания равно 4 см. найдите площадь боковой поверхности призмы.

причины поражения русских войск в борьбе с монголами?

Заполните пропуски положительной или отрицательной формами must, have to, had to, have had to, should.

a. I really do think you ___________ get your hair cut.

b. Careful, darling. You ___________ play with matches. They’re too dangerous.

c. My wife suddenly became ill in the middle of the night and I ____ call the doctor.

d. I’m overweight. The doctor said I _________ eat too many sweets or potatoes.

e. I like Saturday because I ___________ get up early.

f. A. Why have you got so much money on you? You _______ keep it in the bank.

   B. I know. But today’s the day I _________ pay my employees.

g. It’s my mother’s birthday next week. I _______ remember to buy her a present and a card.

h. No one likes __________ work at weekends.

i. You _______________ come with me if you don’t want to. I don’t mind going on my own. You stay here if you like.

j. I have a really bad memory for phone numbers. I ___________ look them up in the book every time.

k. When I was at school we __________ wear a uniform. Everybody hated it.

l. You ______________ touch electrical appliances if you’ve got wet hands. You could kill yourself.

m. She has a private income. She ______ never ______ do one day’s work in the whole of her life.

пятый член  геометрической прогрессии (bn), равен 1 1/2, а знаменатель прогрессии равен -1/2. найдите сумму пяти членов этой прогрессии