题目

新定义：有三个内角相等的四边形叫做三等角四边形. （1） 在三等角四边形 中， ，那么 °； （2） 如图1，折叠平行四边形纸片 ，使顶点 ， 分别落在边 ， 上的点 ， 处，折痕分别为 ， .求证：四边形 是三等角四边形； （3） 如图2，在三等角四边形 中， ，若 ，求 的取值范围. Ma Lili’s parents are going to give a birthday party for her. She’s going to be fourteen years old. Ma Lili has a lot of friends. They are going to come to the party. They are girls from Ma Lili’s school. There are twenty-five of them. Ma Lili’s mother is making birthday cakes for the party. They are very nice cakes. Ma Lili says to her mother, “Mum, you’re very nice. Thank you for your nice cakes. ” Her father is going shopping. He buys a lot of apples, bananas, oranges and pears. It’s four o’clock in the afternoon. Now everything is ready. The party begins in thirty minutes. 1. Who is going to give Ma Lili a birthday party? A. Ma Lili    B. Her friends   C. Her teacher   D. Her parents 2. How many people are coming to Ma Lili’s party? A. Two      B. Twenty      C. Twenty-one     D. Twenty-five 3. Her mother _____ for her party. A. is making cakes   B. is shopping   C. is buying apples   D. makes a cake 4. How old is Ma Lili going to be? A. 12      B. 13      C. 14       D. 20 5. What time does the party begin? A. At four                    B. At half past four C. After five o’clock     D. At about six o’clock