已知菱形的面积为24cm2，一条对角线长为6cm，则这个菱形的周长是______厘米．
如图所示：
∵菱形的面积等于对角线乘积的一半，AC=6cm，S菱形ABCD=24cm2，
∴BD=8cm，AO=3cm，BO=4cm，
在Rt△ABO中，AB2=AO2+BO2，
即有AB2=32+42，
解得：AB=5cm，
∴菱形的周长=4×5=20cm．
故答案为：20．
| 信息匹配。 | ||
| 下面是一篇应用文及其应用场合的信息，请阅读下列应用文和相关信息，并按照要求匹配信息。 首先，请阅读下列的应用文： A. Las Vegas Las Vegas is really a fascinating city, where you can dine in the finest restaurants, shop in the most luxurious stores, and watch world-class entertainment. Among them, the most attractive thing is gambling. Maybe you will become a millionaire or lose all your money overnight. What's so clever about Las Vegas is that it makes absolutely certain that you have such a good time you don't mind losing a bit of money along the way; that's why they don't even call it "gambling" any more, but "gaming". B. Egypt: The old Nile brought about the civilization of Egypt; people there regard it as "the mother river" of them. On both sides of the Nile stand noble pyramids which were built as the bombs of the ancient pharaohs. And the constructions are beyond people's imagination. Along with the Great Pyramid of Giza in Egypt, the Great Sphinx is one of the greatest and most studied monuments of human history. C. Parisian street: Few cities leave the visitors with such vivid impressions. The whole city is something of a work of art. The quiet River Seine, the Eiffel Tower, Palais du Louvre and so on are really feast to your eyes. And annual film festival is held with a refreshing emphasis on art. Few cities can compete with the thousands of cafes, bars and restaurants that line every Parisian street. And along the street you will be fascinated by the beautiful window shows of various clothes. D. Kitzbuhel: Kitzbuhel is a paradise for all the skiers. With fine weather and breath-taking scenery, it is a world-class ski resort. Every winter, thousands of people come from all parts of the world to challenge themselves. If you can't ski, don't worry. The town offers many shops, café and a variety of entertainment. E. Jerusalem: As the cultural center and biggest center and biggest city in the region, Jerusalem is regarded as a holy place by Jews, Muslims and Christians. For Jews, it is where their ancestors built the first and second temples. Muslims knew it was the place where the Prophet Mohammed passed up to heaven. For Christians the city was the scene of Jesus' life. However, since the war broke out, people there have suffered a lot, the situation has been tense, and peace is just a dream. F. Mauritius Mauritius is an island lying off the southeast Africa in the Indian Ocean, which is rich in history, natural beauty and culture. The pleasant climate and scenery provides the perfect setting to enjoy everything. The sea is full of colorful life that lives around the coral reef. This makes Mauritius a wonderful place for swimming and diving. The larger number of interesting fish means it is also an exciting place for those who like to go fishing. | ||
| 请阅读以下个人信息，然后匹配到合适的地方。 Smith is a professor who does research on ancient buildings. He has been to many historical sites and discovered a lot of valuable materials. This month, his university gives a reward to him for his great contributions. So now an idea of traveling to a new place to continue his study has come into his mind. Though Lola is a woman reporter, she is brave enough to go deep into any places even those at conflicts. This year, she was honored as "Rose of Front", which made her very proud of herself. She has been working to tell the truth in her reports, since she believes it's journalists' duty to inform people of what's going on around the world, good or bad. Alice and Simon are going to get married. Interested in skiing much, they are also fond of ball games and water sports. They are planning their wedding in a special place, which has beautiful scenery, silver sand and delicious seafood as well as luxurious hotels, where they can enjoy themselves. Jane is a modern girl, who is a crazy fan of rock music and films. She has a romantic dream, that is, one day, she will go to a beautiful place to appreciated all the attractive music and films with a cup of coffee in her hand. Tom is really depressed these days. Owing to his bad management, his company closed. He wants to go to a place to try his fortune so that he can start his business again in the near future. | ||
|