AMC 8 2005 Problem 19
AMC8 2005 年第 19 题
四边形与多边形★★★☆☆
What is the perimeter of trapezoid ABCD ?
梯形 ABCD 的周长是多少？
- A.180
- B.188
- C.196
- D.200
- E.204
正确答案 · Correct Answer
A
解析 · Solution
Solution 1
Draw altitudes from and to base to create a rectangle and two right triangles. The side opposite is equal to 50. The bases of the right triangles can be found using Pythagorean or special triangles to be 18 and 7. Add it together to get AD=18+50+7=75. The perimeter is 75+30+50+25=180.
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