在一个三角形里,三个内角关系如下:当∠1大于∠2与∠3的度数之和时,这个三角形一定是钝角三角形.______.
因为∠2+∠3<∠1,且∠2+∠3+∠1=180°,所以只有当∠1大于90度的时候,∠2+∠3才会小于∠1,
所以∠1是钝角,所以这个三角形一定是钝角三角形;
所以原题说法正确,
故答案为:正确.
在一个三角形里,三个内角关系如下:当∠1大于∠2与∠3的度数之和时,这个三角形一定是钝角三角形.______.
因为∠2+∠3<∠1,且∠2+∠3+∠1=180°,所以只有当∠1大于90度的时候,∠2+∠3才会小于∠1,
所以∠1是钝角,所以这个三角形一定是钝角三角形;
所以原题说法正确,
故答案为:正确.
阅读理解。 |
Mark was walking home from school one day when he saw the boy in front of him fall over and drop all |
1. When Mark met him the first time, Bill was going ________. |
[ ] |
A. to have a basketball game |
2. From what Bill was carrying, we can know that he ________. |
[ ] |
A. was a good student B. liked sports and music C. liked all the subjects in school D. was a good friend |
3. Mark and Bill ________. |
[ ] |
A. were in the same middle school and high school B. were in the same middle school but not in the same high school C. often had lunch together at school D. had known each other before they began to study in middle school |
4. In this passage, the phrase "broken up" means "_______". |
[ ] |
A. 相处很好 B. 和好如初 C. 关系破裂 D. 保持联系 |
5. When Mark helped Bill to pick up some of his things, he . |
[ ] |
A. knew he could save Bill's life B. knew who Bill was and wanted to help him C. didn't know why he was going to help him D. didn't know what he was doing was very important to Bill |