{"common":{"save":0,"post_id":"7713","level":2,"total":10,"point":10,"point_extra":0},"segment":[{"id":"1878","post_id":"7713","mon_id":"1159414","chapter_id":"1159460","question":"<p>Di\u1ec7n tích c\u1ee7a hình tròn có chu vi 125,6 dm là:<\/p>","options":["<strong>A.<\/strong> 1256 dm²","<strong>B.<\/strong> 1265 dm²","<strong>C.<\/strong> 1526 dm²","<strong>D.<\/strong> 1625 dm²"],"correct":"1","level":"2","hint":"","answer":"<p>Ch\u1ecdn <span style=\"color:#16a085;\"><strong>A.<\/strong> 1256 dm².<\/span><\/p><p>Bán kính c\u1ee7a hình tròn có chu vi 125,6 dm là <strong>125,6 : 3,14 : 2 = 20<\/strong> (dm).<br \/>Di\u1ec7n tích hình tròn \u0111ó là <strong>20 x 20 x 3,14 = 1256<\/strong> (dm²).<\/p>","type":"choose","extra_type":"classic","time":"0","user_id":"131","test":"0","date":"2024-09-24 01:40:37","option_type":"txt","len":2},{"id":"1880","post_id":"7713","mon_id":"1159414","chapter_id":"1159460","question":"<p>Chu vi c\u1ee7a hình tròn có di\u1ec7n tích 50,24 cm² là:<\/p>","options":["<strong>A.<\/strong> 24,12 cm","<strong>B.<\/strong> 24,32 cm","<strong>C.<\/strong> 25,12 cm","<strong>D.<\/strong> 25,32 cm"],"correct":"3","level":"2","hint":"","answer":"<p>Ch\u1ecdn <span style=\"color:#16a085;\"><strong>C.<\/strong> 25,12 cm.<\/span><\/p><p>Hình tròn có di\u1ec7n tích 50,24 cm² nên 3,14 x r x r = 50,24.<\/p><p>Do \u0111ó r x r = 50,24 : 3,14 = 16 mà 16 = 4 x 4 nên bán kính c\u1ee7a hình tròn là 4 cm.<\/p><p>Chu vi c\u1ee7a hình tròn là: 3,14 x 4 x 2 = 25,12 (cm).<\/p>","type":"choose","extra_type":"classic","time":"0","user_id":"131","test":"0","date":"2024-09-24 01:43:37","option_type":"txt","len":1},{"id":"1881","post_id":"7713","mon_id":"1159414","chapter_id":"1159460","question":"<p>Tính chi\u1ec1u cao c\u1ee7a m\u1ed9t tam giác có di\u1ec7n tích b\u1eb1ng 30 cm² và \u0111\u1ed9 dài \u0111áy b\u1eb1ng 6cm.<\/p>","options":["<strong>A.<\/strong> 8 cm","<strong>B.<\/strong> 10 cm","<strong>C.<\/strong> 10,5 cm","<strong>D.<\/strong> 12 cm"],"correct":"2","level":"2","hint":"","answer":"<p>Ch\u1ecdn <span style=\"color:#16a085;\"><strong>B.<\/strong> 10 cm.<\/span><\/p><p>Chi\u1ec1u cao c\u1ee7a tam giác là <span class=\"math-tex\">$\\dfrac{30\\times 2}{6}$<\/span> = 10 (cm).<\/p>","type":"choose","extra_type":"classic","time":"0","user_id":"131","test":"0","date":"2024-09-24 01:46:07","option_type":"txt","len":0}]}
