描述

1. nh rn c9 n h I a : AB, va BC dl nh B, din h C h I a : al n h Ba g 6c I a : g6c dln h A; g6c dln h S; g 6 c al n h C Ducm g c a o c u a ta m g i a c I a OO(:l n t h a n g ke t u mot dln h va vuong g o c v6'i c� n h doi di� n (c� n h day). c H DQ d a i cua dliong ca o Ia chieu cao c u a ta m giac. M¢t ta m g i a c c6 3 duang cao. 2. Ta m gi ac ABC c6: A H Ia chieu cao t u'ong ung voi c� n h day BC; A Bl la chieu cao tuang ung v6'i c9 n h AC; CK I a c h ieu ca o tuong U'n g v6'i c9 n h AB. Ch u vi: P = a + b + c (P: ch u vi; a, b , c I a a(> dai ba c9 n h ta m g i a c) Di$n tich: S == AHxBC 2 _ BixAC CKxA B 2 sX2 Aa y a = h- ; tro n g u Ao h I a ' c h 1eu cao tuong ling c9 n h a. Ch .1 e u ca o h = -- ; Cc;I n h u "' 3. Ca c d� ng H1 n h ta m . A' ta m g ia c Hin h vu6ng (c6 m¢t g6c vu6ng) Hlnh can (2 cgnh nhau) Hlnh ta m gi a c cteu (3 cc;mh bang nhau) A rc h i m ed es Aschoo 3 A RC H I M E D ES SCH O O L I L c A. c o�NG sAt TAP A . T in h c a c yeu t o cua ta m g i a c Bai 1 . D i e n ket q u a v a o 6 trong (v6i a I a ch i eu d a i m¢t C9 n h cua hl n h ta m g ia c v a h Ia c h i e u ca o tlfon g U'n g cua c� n h do). �--\ a i ....----,------.-- I ,-- O,Sdm i 25 cm ! �----- Bai 2. f)i en ket q u a vao 6 trong (v-a i ta m giac vu6ng). vuong 1 C�n h g 6c vuong 2 I 2 5 rn Di�n tich tam qiac l 1 I 2 1 cm2 _ __ 2,5 dm L 4 d m2 _____ ...... . .. .. . .. 5 ,2d m '""··· ··· 1 8m l I 2 5d m 4d m I C� n h g6c . 7cm 3,8m 400cm 4 5 cm ........ ....... .., Sdm 4d m -·· 9 dm2 __ _ __.......� 1 00 c m 2 �·�·········· Bai 3. Tfnh di$n tfch tam giac/ biet d9 dai m¢t c�nh Ia 1 2cm va chieu cao tVdng U'ng Ia Scm. Bai 4. M9t tam b ien bao g iao thong hl n h ta m g iac c6 tong c9nh day va chieu cao tvang ung Ia 32m, C<;l nh day hon chieu cao S m . Tfn h d i� n tfch tam bien ao . Rise above oneself a n d grasp the world n Lf n g L3 h ca n h d tam n ---

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