{"common":{"save":0,"post_id":"7703","level":2,"total":10,"point":10,"point_extra":0},"segment":[{"id":"1819","post_id":"7703","mon_id":"1159414","chapter_id":"1159460","question":"<p>Chu vi hình tròn có \u0111\u01b0\u1eddng kính 9 cm là<\/p>","options":["<strong>A.<\/strong> 26,28 cm","<strong>B.<\/strong> 28,2 cm","<strong>C.<\/strong> 28,26 cm","<strong>D.<\/strong> 26,8 cm"],"correct":"3","level":"2","hint":"","answer":"<p>Ch\u1ecdn <span style=\"color:#16a085;\"><strong>C.<\/strong> 28,26 cm.<\/span><\/p><p>Chu vi hình tròn là: 3,14 x 9 = 28,26 (cm).<\/p>","type":"choose","extra_type":"classic","time":"0","user_id":"131","test":"0","date":"2024-09-22 04:52:01","option_type":"txt","len":1},{"id":"1820","post_id":"7703","mon_id":"1159414","chapter_id":"1159460","question":"<p>\u0110\u01b0\u1eddng kính c\u1ee7a hình tròn có chu vi 39,564 dm là:<\/p>","options":["<strong>A.<\/strong> 12,6 dm","<strong>B. <\/strong>10,6 dm","<strong>C.<\/strong> 16,2 dm","<strong>D.<\/strong> 16 dm"],"correct":"1","level":"2","hint":"","answer":"<p>Ch\u1ecdn <span style=\"color:#16a085;\"><strong>A.<\/strong> 12,6 dm.<\/span><\/p><p>\u0110\u01b0\u1eddng kính c\u1ee7a hình tròn \u0111ó là 39,564 : 3,14 = 12,6 (dm).<\/p>","type":"choose","extra_type":"classic","time":"0","user_id":"131","test":"0","date":"2024-09-22 04:54:27","option_type":"txt","len":0},{"id":"1822","post_id":"7703","mon_id":"1159414","chapter_id":"1159460","question":"<p>Bán kính c\u1ee7a hình tròn có chu vi 37,052 mm là:<\/p>","options":["<strong>A.<\/strong> 6 mm","<strong>B.<\/strong> 5,9 mm","<strong>C.<\/strong> 5,8 mm","<strong>D.<\/strong> 5,7 mm"],"correct":"2","level":"2","hint":"","answer":"<p>Ch\u1ecdn <span style=\"color:#16a085;\"><strong>B.<\/strong> 5,9 mm.<\/span><\/p><p>T\u1eeb công th\u1ee9c tính chu vi C = r x 2 x 3,14, ta có th\u1ec3 tính bán kính theo công th\u1ee9c <br \/>r = C : 2 : 3,14 hay r = C : 3,14 : 2.<\/p><p>Bán kính c\u1ee7a \u0111\u01b0\u1eddng tròn \u0111ó là 37,052 : 3,14 : 2 = 5,9 (mm).<\/p>","type":"choose","extra_type":"classic","time":"0","user_id":"131","test":"0","date":"2024-09-22 04:57:31","option_type":"txt","len":0}]}
