Đề kiểm tra
Hä vµ tªn: .............................................................................Líp.................................
KiÓm tra : H×nh häc ( Ch¬ng II)
Thêi gian lµm bµi: (45 phót)
§iÓm Lêi phª
§Ò bµi:
Bµi 1: (2 ®iÓm): Trong c¸c c©u sau, c©u nµo ®óng, c©u nµo sai? §¸nh dÊu “x” vµo c©u lùa chän
C©u
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§óng
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Sai
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1. Tam gi¸c cã mét gãc 45o lµ tam gi¸c vu«ng c©n
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2. Tam gi¸c cã hai c¹nh b»ng nhau vµ mét gãc b»ng 60o lµ tam gi¸c ®Òu
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3. Mçi gãc ngoµi cña tam gi¸c th× b»ng tæng hai gãc trong kh«ng kÒ víi nã cña tam gi¸c ®ã
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4.NÕu ba gãc cña tam gi¸c nµy, b»ng ba gãc cña tam gi¸c kia th× hai tam gi¸c ®ã b»ng nhau.
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Bµi 2: (3 ®iÓm) Tam gi¸c cã ®é dµi ba c¹nh lµ 24cm, 18cm, 30cm, cã ph¶i lµ tam gi¸c vu«ng kh«ng?
Bµi gi¶i
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Bµi 3 (5 ®iÓm):Cho tam gi¸c c©n ABC cã AB = AC = 5cm, BC = 8cm, kÎ AH vu«ng gãc víi BC( H
a) Chøng minh HB = HC vµ
b) TÝnh ®é dµi AH
c) KÎ HD vu«ng gãc víi AB(D, kÎ HE vu«ng gãc víi AC ( E ) . Chøng minh tam gi¸c HDE lµ tam gi¸c c©n.
Bµi gi¶i