In the figure(http://hk.geocities.com/ken1ken1232003/quadrilateral.bmp), the diagonals AC and BD of quadrilateral ABCD intersect at E. the quadrilateral satisfies the following conditions:
I. AB = DC
II. ∠BAC = ∠CDB
(a) Prove that AC = BD,
(b) If ∠BAC = 90゜, AB = 8 and BD = 15, find BC.
英文數學題9,急急
2007-01-13 2:41 am
回答 (2)
2007-01-13 3:10 am
✔ 最佳答案
a)Since
AB = DC(given)
∠BAC = ∠CDB(given)
BC=BC(common side)
So,△BAC≡CDB(A.S.S.)
So,AC = BD(corresponding side of ≡△)
b)Since
∠BAC = 90(given)
∠CDB= 90(corresponding ∠ of ≡△)
AB = 8(given)
DC = 8(corresponding side of ≡△)
in△CDB,
BC=√(15^2-8^2)---------(Phtya.theo)
BC=11
參考: BY EASON MENSA
2007-01-13 3:09 am
(a)
Prove that △ABE全等於△DCE,
AB = DC (given)
∠BAC = ∠CDB (given)
∠AEB=∠DEC(vert. opp∠s)
∴△ABE全等於△DCE
∴AC = BD(corr. sides ～△s)
(b)
I don't know..
Prove that △ABE全等於△DCE,
AB = DC (given)
∠BAC = ∠CDB (given)
∠AEB=∠DEC(vert. opp∠s)
∴△ABE全等於△DCE
∴AC = BD(corr. sides ～△s)
(b)
I don't know..
收錄日期: 2021-04-13 14:20:09
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20070112000051KK03117