C\u00e2u 7:<\/b>\u00a0Trong c\u00e1c m\u1ec7nh \u0111\u1ec1 sau, m\u1ec7nh \u0111\u1ec1 n\u00e0o \u0111\u00fang?<\/p>\n
A. M\u1ed7i h\u00ecnh \u0111a di\u1ec7n c\u00f3 \u00edt nh\u1ea5t 8 c\u1ea1nh<\/p>\n
B. M\u1ed7i h\u00ecnh \u0111a di\u1ec7n c\u00f3 \u00edt nh\u1ea5t 7 c\u1ea1nh<\/p>\n
C. M\u1ed7i h\u00ecnh \u0111a di\u1ec7n c\u00f3 \u00edt nh\u1ea5t 6 c\u1ea1nh<\/p>\n
D. M\u1ed7i h\u00ecnh \u0111a di\u1ec7n c\u00f3 \u00edt nh\u1ea5t 9 c\u1ea1nh<\/p>\n
C\u00e2u 8:<\/b>\u00a0Trong c\u00e1c m\u1ec7nh \u0111\u1ec1 sau, m\u1ec7nh \u0111\u1ec1 n\u00e0o \u0111\u00fang?<\/p>\n
A. M\u1ed7i h\u00ecnh \u0111a di\u1ec7n c\u00f3 \u00edt nh\u1ea5t 8 \u0111\u1ec9nh<\/p>\n
B. M\u1ed7i h\u00ecnh \u0111a di\u1ec7n c\u00f3 \u00edt nh\u1ea5t 6 \u0111\u1ec9nh<\/p>\n
C. M\u1ed7i h\u00ecnh \u0111a di\u1ec7n c\u00f3 \u00edt nh\u1ea5t 5 \u0111\u1ec9nh<\/p>\n
D. M\u1ed7i h\u00ecnh \u0111a di\u1ec7n c\u00f3 \u00edt nh\u1ea5t 4 \u0111\u1ec9nh<\/p>\n
C\u00e2u 9:<\/b>\u00a0Trong c\u00e1c m\u1ec7nh \u0111\u1ec1 sau, m\u1ec7nh \u0111\u1ec1 n\u00e0o \u0111\u00fang?<\/p>\n
A. T\u1ed3n t\u1ea1i m\u1ed9t h\u00ecnh \u0111a di\u1ec7n c\u00f3 s\u1ed1 m\u1eb7t l\u1edbn h\u01a1n s\u1ed1 c\u1ea1nh<\/p>\n
B. T\u1ed3n t\u1ea1i m\u1ed9t h\u00ecnh \u0111a di\u1ec7n c\u00f3 s\u1ed1 m\u1eb7t l\u1edbn h\u01a1n s\u1ed1 \u0111\u1ec9nh<\/p>\n
C. Trong m\u1ed9t h\u00ecnh \u0111a di\u1ec7n s\u1ed1 m\u1eb7t lu\u00f4n l\u1edbn h\u01a1n ho\u1eb7c b\u1eb1ng s\u1ed1 \u0111\u1ec9nh<\/p>\n
D. T\u1ed3n t\u1ea1i m\u1ed9t h\u00ecnh \u0111a di\u1ec7n c\u00f3 s\u1ed1 \u0111\u1ec9nh l\u1edbn h\u01a1n s\u1ed1 c\u1ea1nh<\/p>\n
C\u00e2u 10:<\/b>\u00a0Trong c\u00e1c m\u1ec7nh \u0111\u1ec1 sau, m\u1ec7nh \u0111\u1ec1 n\u00e0o \u0111\u00fang?<\/p>\n
A. Trong m\u1ed9t h\u00ecnh \u0111a di\u1ec7n n\u1ebfu s\u1ed1 m\u1eb7t v\u00e0 s\u1ed1 \u0111\u1ec9nh l\u1ebb th\u00ec s\u1ed1 c\u1ea1nh ch\u1eb5n<\/p>\n
B. Trong m\u1ed9t h\u00ecnh \u0111a di\u1ec7n n\u1ebfu s\u1ed1 m\u1eb7t v\u00e0 s\u1ed1 \u0111\u1ec9nh l\u1ebb th\u00ec s\u1ed1 c\u1ea1nh l\u1ebb<\/p>\n
C. Trong m\u1ed9t h\u00ecnh \u0111a di\u1ec7n n\u1ebfu s\u1ed1 m\u1eb7t v\u00e0 s\u1ed1 c\u1ea1nh l\u1ebb th\u00ec s\u1ed1 \u0111\u1ec9nh l\u1ebb<\/p>\n
D. Trong m\u1ed9t h\u00ecnh \u0111a di\u1ec7n n\u1ebfu s\u1ed1 \u0111\u1ec9nh v\u00e0 s\u1ed1 c\u1ea1nh l\u1ebb th\u00ec s\u1ed1 m\u1eb7t l\u1ebb<\/p>\n
C\u00e2u 11:<\/b>\u00a0Trong c\u00e1c m\u1ec7nh \u0111\u1ec1 sau, m\u1ec7nh \u0111\u1ec1 n\u00e0o \u0111\u00fang?<\/p>\n
Cho h\u00ecnh \u0111a di\u1ec7n (H) c\u00f3 c\u00e1c m\u1eb7t l\u00e0 nh\u1ee9ng tam gi\u00e1c, m\u1ed7i \u0111\u1ec9nh l\u00e0 \u0111\u1ec9nh chung c\u1ee7a \u0111\u00fang 3 m\u1eb7t. G\u1ecdi s\u1ed1 c\u00e1c \u0111\u1ec9nh, c\u1ea1nh, m\u1eb7t c\u1ee7a h\u00ecnh \u0111a di\u1ec7n (H) l\u1ea7n l\u01b0\u1ee3t l\u00e0 d, c, m. Khi \u0111\u00f3:<\/p>\n
A. d > m\u00a0\u00a0\u00a0B. d < m\u00a0\u00a0\u00a0C. d = m\u00a0\u00a0\u00a0D. d + m = c<\/p>\n
C\u00e2u 12:<\/b>\u00a0M\u1ed7i \u0111\u1ec9nh c\u1ee7a h\u00ecnh \u0111a di\u1ec7n l\u00e0 \u0111\u1ec9nh chung c\u1ee7a \u00edt nh\u1ea5t bao nhi\u00eau m\u1eb7t?<\/p>\n
A. 2 m\u1eb7t\u00a0\u00a0\u00a0B. 3 m\u1eb7t\u00a0\u00a0\u00a0C. 4 m\u1eb7t\u00a0\u00a0\u00a0D. 5 m\u1eb7t<\/p>\n
H\u01b0\u1edbng d\u1eabn gi\u1ea3i v\u00e0 \u0110\u00e1p \u00e1n<\/b><\/p>\n C\u00e2u 9:<\/b><\/p>\n C\u00e1ch 1. D\u00f9ng c\u00f4ng th\u1ee9c (1)<\/p>\n C\u00e1ch 2. T\u1eeb h\u00ecnh b\u00e1t di\u1ec7n \u0111\u1ec1u suy ra B l\u00e0 m\u1ec7nh \u0111\u1ec1 \u0111\u00fang<\/p>\n C\u00e1ch 3. C\u0169ng c\u00f3 th\u1ec3 d\u00f9ng c\u00f4ng th\u1ee9c (2) v\u00e0 (3) nh\u01b0 sau: V\u00ec m\u1ed7i m\u1eb7t c\u00f3 \u00edt nh\u1ea5t ba c\u1ea1nh, n\u00ean theo (2) ta c\u00f3 2c \u2265 3m , suy ra c > m . Do \u0111\u00f3 m\u1ec7nh \u0111\u1ec1 A sai. T\u01b0\u01a1ng t\u1ef1 t\u1eeb (3) suy ra m\u1ec7nh \u0111\u1ec1 D sai. T\u1eeb h\u00ecnh t\u1ee9 di\u1ec7n suy ra C sai. V\u1eady B l\u00e0 m\u1ec7nh \u0111\u1ec1 \u0111\u00fang.<\/p>\n C\u00e2u 10:<\/b><\/p>\n D\u00f9ng c\u00f4ng th\u1ee9c \u01a0le.<\/p>\n C\u00e2u 11:<\/b><\/p>\n Ta c\u00f3 3d = 3m = 2c, suy ra C \u0111\u00fang<\/p>\n C\u00e2u 7:\u00a0Trong c\u00e1c m\u1ec7nh \u0111\u1ec1 sau, m\u1ec7nh \u0111\u1ec1 n\u00e0o \u0111\u00fang? A. M\u1ed7i h\u00ecnh \u0111a di\u1ec7n c\u00f3 \u00edt nh\u1ea5t 8 c\u1ea1nh B. M\u1ed7i h\u00ecnh \u0111a di\u1ec7n c\u00f3 \u00edt nh\u1ea5t 7 c\u1ea1nh C. M\u1ed7i h\u00ecnh \u0111a di\u1ec7n c\u00f3 \u00edt nh\u1ea5t 6 c\u1ea1nh D. M\u1ed7i h\u00ecnh \u0111a di\u1ec7n c\u00f3 \u00edt nh\u1ea5t 9 c\u1ea1nh C\u00e2u 8:\u00a0Trong c\u00e1c m\u1ec7nh \u0111\u1ec1 […]<\/p>\n","protected":false},"author":3,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_mi_skip_tracking":false,"tdm_status":"","tdm_grid_status":""},"categories":[157],"tags":[1450,1448],"yoast_head":"\n\n\n
\n 7-C<\/td>\n 8-D<\/td>\n 9-B<\/td>\n 10-A<\/td>\n 11-C<\/td>\n 12-B<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n