{"common":{"save":0,"post_id":"7728","level":2,"total":10,"point":10,"point_extra":0},"segment":[{"id":"1997","post_id":"7728","mon_id":"1159414","chapter_id":"1159461","question":"<p>M\u1ed9t hình thang có \u0111áy l\u1edbn b\u1eb1ng 28 cm, \u0111áy bé b\u1eb1ng <span class=\"math-tex\">$\\dfrac{3}{7}$<\/span> \u0111áy l\u1edbn, chi\u1ec1u cao b\u1eb1ng <span class=\"math-tex\">$\\dfrac{3}{5}$<\/span> \u0111áy l\u1edbn. V\u1eady di\u1ec7n tích c\u1ee7a hình thang \u0111ó là:<\/p>","options":["<strong>A.<\/strong> 336 cm²","<strong>B.<\/strong> 326 cm²","<strong>C.<\/strong> 316 cm²","<strong>D.<\/strong> 346 cm²"],"correct":"1","level":"2","hint":"","answer":"<p>Ch\u1ecdn <span style=\"color:#16a085;\"><strong>A.<\/strong> 336 cm².<\/span><\/p><p>\u0110\u1ed9 dài \u0111áy bé là: <span class=\"math-tex\">$28\\times\\dfrac{3}{7}=12$<\/span> (cm).<\/p><p>Chi\u1ec1u cao c\u1ee7a hình thang \u0111ó là: <span class=\"math-tex\">$28\\times\\dfrac{3}{5}=16,8$<\/span> (cm).<\/p><p>Di\u1ec7n tích hình thang \u0111ó là: <span class=\"math-tex\">$\\dfrac{(28+12)\\times16,8}{2}=336$<\/span> (cm²).<\/p>","type":"choose","extra_type":"classic","time":"0","user_id":"131","test":"0","date":"2024-09-26 02:14:11","option_type":"txt","len":1},{"id":"1999","post_id":"7728","mon_id":"1159414","chapter_id":"1159461","question":"<p>M\u1ed9t hình tròn có di\u1ec7n tích là 200,96 m². Chu vi hình tròn \u0111ó là:<\/p>","options":["<strong>A.<\/strong> 16,48 m","<strong>B.<\/strong> 28,32 m","<strong>C.<\/strong> 48 m","<strong>D.<\/strong> 50,24 m"],"correct":"4","level":"2","hint":"","answer":"<p>Ch\u1ecdn <span style=\"color:#16a085;\"><strong>D.<\/strong> 50,24 m.<\/span><\/p><p>Tích c\u1ee7a bán kính và bán kính là: 200,96 : 3,14 = 64.<br \/>Vì 64 = 8 x 8 nên bán kính c\u1ee7a hình tròn \u0111ó là 8 m.<br \/>Chu vi hình tròn \u0111ó là: 3,14 x 8 x 2 = 50,24 (m).<\/p>","type":"choose","extra_type":"classic","time":"0","user_id":"131","test":"0","date":"2024-09-26 02:17:34","option_type":"txt","len":0},{"id":"2001","post_id":"7728","mon_id":"1159414","chapter_id":"1159461","question":"<p>M\u1ed9t hình tròn có chu vi là 21,352 cm. Di\u1ec7n tích hình tròn \u0111ó là:<\/p>","options":["<strong>A.<\/strong> 36,2984 cm²","<strong>B.<\/strong> 36,2974 cm²","<strong>C.<\/strong> 36,2948 cm²","<strong>D.<\/strong> 36,2944 cm²"],"correct":"1","level":"2","hint":"","answer":"<p>Ch\u1ecdn <span style=\"color:#16a085;\"><strong>A.<\/strong> 36,2984 cm².<\/span><\/p><p>\u0110\u1ed9 dài bán kính c\u1ee7a hình tròn \u0111ó là: 21,352 : 3,14 : 2 = 3,4 (cm).<br \/>Di\u1ec7n tích hình tròn \u0111ó là: 3,14 x 3,4 x 3,4 = 36,2984 (cm²).<\/p>","type":"choose","extra_type":"classic","time":"0","user_id":"131","test":"0","date":"2024-09-26 02:20:56","option_type":"txt","len":2}]}
