1.Find the mistakes
圖片參考：http://imgcld.yimg.com/8/n/HA00510450/o/701006280068013873433390.jpg
2.
圖片參考：http://imgcld.yimg.com/8/n/HA00510450/o/701006280068013873433401.jpg
(a) state the order of ratational symmetry about PQ
(b) Is DG an axis of ratational symmetry? If yes, state the order of ratational symmetry
(c)Is CH an axis of ratational symmetry? If yes, state the order of ratational symmetry
(d)Is MN an axis of ratational symmetry? If yes, state the order of ratational symmetry
(e) How many axes of ratational symmetry are there?
(f) How many planes of reflection are there?
MATHS問題
2010-06-28 10:34 pm
回答 (2)
2010-06-29 3:08 am
✔ 最佳答案
1. Slope of L1 is infinity ( = tan 90 degree)Slope of L2 is 0 ( = tan 0 degree)
(For slope = 1, angle makes with x - axis = arctan 1 = 45 degree.)
2.
(a) PQ is order 4.
(b)DG is order 3.
(c) CH is not an axis of rotational symmetry.
(d)MN is order 2.
(e) A cube has 13 axes of rotational symmetry. ( 3 order 4, 4 order 3 and 6 order 2). See video on www.mathexpression.com/rotational-symmetry.html
(f)A cube has 9 planes of reflection symmetry. Refer to www.shcc.edu.hk/~annie/symmetry.html
2010-06-29 12:35 am
the slope of L1 should be "infinity"
There are so many words in Q2, so I feel confused.
Simon Yau
There are so many words in Q2, so I feel confused.
Simon Yau
參考: Simon Yau
收錄日期: 2021-04-13 17:20:40
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20100628000051KK00680