题目

如图，在 中，AD是高，E、F分别是AB、AC的中点， （1） ， ，求四边形AEDF的周长； （2） 与AD有怎样的位置关系，证明你的结论. 答案：解：∵AD是高，E、F分别是AB、AC的中点， ∴DE=AE= 12 AB= 12 ×10=5，DF=AF= 12 AC= 12 ×8=4， ∴四边形AEDF的周长=AE+DE+DF+AF=5+5+4+4=18； 解：EF垂直平分AD. 证明：∵DE=AE，DF=AF， ∴EF垂直平分AD. 阅读理解 　　Many famous people had dreams when they were young．They often worked hard to make their dreams come true． 　　When I was only 13 years old, I first thought about what I should do in the future．I used to dream about being a basketball player, a soccer player, or a baseball player．However, I gave up these dreams because I was too short．Then I thought about going into music, so I bought a guitar．But I couldn't play it very well．Then I had to give up my dream again．After that I thought about being a reporter and I worked really hard at it．At the age of 25, my dream came true and I became a reporter． 　　Finally, I learned the truth about making dreams come true．I should never give up and I must work hard． Answer the questions according to the passage． 1．How old was the writer when he first had a dream? 2．Why did he give up being a basketball player? 3．How many dreams did he give up? 4．Did his dream come true at last? 5．What can you learn from this passage?