PP-PS-T1-179

[whoisallan]

 PS1-179 19312-!-item-!-187;#058&012220
If two sides of a triangle have lengths 2 and 5, which of the following could be the perimeter of the triangle?
1)9
2)15
3)19

(A) None
(B) I only
(C) II only
(D) II and III only
(E) I, II, and III
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設第三邊=x
這題我是用2邊長大於第3邊, so x>7
所以我覺得3)可以
答案是A...拜求思路

[Huang Hsin-Yi]

 PS1-179 19312-!-item-!-187;#058&012220
If two sides of a triangle have lengths 2 and 5, which of the following could be the perimeter of the triangle?
1)9
2)15
3)19

(A) None
(B) I only
(C) II only
(D) II and III only
(E) I, II, and III
----------------------------------------------------------------------------
設第三邊=x
這題我是用2邊長大於第3邊, so x>7
對呀,就是這個概念,so x<2+5

所以我覺得3)可以
答案是A...拜求思路

[whoisallan]

tks
真的是頭暈了我...


so 7>x>3
周長應介於 14>perimeter>10

ANS:A