Hình chữ nhật là loại hình cơ bản trong hình học. Với chu vi không đổi thì hình chữ nhật có diện tích lớn nhất khi nó là hình vuông.
Yêu cầu: Nhập từ bàn phím số thực P là chu vi hình chữ nhật. Hãy tính diện tích lớn nhất của hình chữ nhật có thể đạt được với chu vi đã cho.
Giới hạn: Số P là số thực dương có giá trị không lớn hơn 1000.
I/Turn into active voice
Someone will have to be found to take her place.
He was made to surrender his passport.
Your money could be put to good use instead of being left idle in the bank.
It is being said that too little money is being spent by the government on roads.
Why wasn’t the car either locked or put into the garage?
This scientific theory has now been proved to be false.
The house where the dead man was found is being guarded by the police to prevent it from being entered and evidence interfered with.
The stones were thrown by a student, who was afterwards led away by the police.
Last year a profit of two million pounds was made in the first six months but this was cancelled by a loss of seventeen million pounds which was made in the second six months.
Why don’t you have your eyes tested?
For a long time the earth was believed to be flat.
II/ Turn into Passive Voice
The local council decided to rebuild the house opposite the college.
Do people use milk for making butter and cheese?
Haven’t you yet found out information about the trains to Hanoi?
My sister often makes me do the washing up.
People believed that the policeman had saved many children from the fire.
If I collected a lot of shells on the beach, I would give you some.
How many books do you give me?
People say he is intelligent.
They are going to build a new school here next summer.
She will have to finish her housework before she watches TV.
The boys talked about the man whom they saw on the street last night.
She always talks about the boy who helped her last week.
Have you thought that there is a beautiful girl on the moon?
How many ways can you solve this problem?
She has him repair the house roof.
They had the boys study their lessons carefully.
They didn’t give him anything because he was too lazy.
No one can do anything unless someone gives us more information.
Why didn’t they mend the roof before it fell in?
They won’t say anything more about the matter if someone returns the stolen gun.
The librarian said that they were starting a new system because people were not returning books.
The boys talked about the man whom they saw on TV last night.
The house which they bought last year was very cheap.
Somebody had cleaned my shoes and brushed my suit.
He suggested allowing council tenants to buy their houses.
Turn into passive
They have eaten all the dinner before they finished the conversation.
Somebody has locked the box and I can’t open it.
They have to pay the bill before the first of the month.
People say that he is the best engineer.
Nobody used that old tractor to plough the hard soil.
Are you sure that nobody was watching you?
Have you known the pupil sitting near the window yet?
They give a serum to a man whom a snake bit.
What does she say?
What made him feel homesick?
Who did they talk about?
Who often play games with the boys?
How many lessons are you going to learn next month?
Before they took exams they had revised their lessons.
Why did people think Halloween was important?
The local council decided to rebuild the house opposite the college.
Do people use milk for making butter and cheese?
Haven’t you yet found out information about the trains to Hanoi?
My sister often makes me do the washing up.
People believed that the policeman had saved many children from the fire