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英文四邊形數學題2(15分)
回答 (2)
2009-02-02 3:37 am
✔ 最佳答案
Every interior angle in a square is 90 degree, so3x = 90
x = 30
The diagonal line BD bisects an interior angle, which gives angleADB = angleABD = 45 degree, so
sin(45 degree) = cos(45 degree) = y/2
√(2)/2 = y/2
y = √(2)
2009-02-02 5:00 am
1.
3x = 90 degrees (prop. of square)
x = 90 degrees / 3
x = 30 degrees
2.
AD
= AB (prop. of square)
= y
so
y² + y² = 2² cm (Pyth. thm)
2y² = 4 cm
y² = 4 cm / 2
y = √2 or -√2(rejected)
y = √2 cm
2009-02-01 21:06:11 補充：
y = √2 but not √2 cm
3x = 90 degrees (prop. of square)
x = 90 degrees / 3
x = 30 degrees
2.
AD
= AB (prop. of square)
= y
so
y² + y² = 2² cm (Pyth. thm)
2y² = 4 cm
y² = 4 cm / 2
y = √2 or -√2(rejected)
y = √2 cm
2009-02-01 21:06:11 補充：
y = √2 but not √2 cm
收錄日期: 2021-04-23 20:21:19
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20090201000051KK01871