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[PP视频全场集锦] 意甲-莫拉塔破门+失空门莱蒂齐亚救主 尤文1-1平贝内文托

[咪咕全场集锦] 意甲-莫拉塔破门+失空门莱蒂齐亚救主 尤文1-1平贝内文托

[进球视频] 莱蒂齐亚突施冷箭破门 贝内文托半场扳平比分

[进球视频] 小基耶萨后场长传 莫拉塔晃开角度低射破门

[红牌罚下] 不满判罚 比赛结束后莫拉塔言语过激被罚下

[错失空门] 尤文连续传递造杀机 莫拉塔门前包抄错失空门

主队：贝内文托
客队：尤文图斯
比赛时间：2020-11-29 01:00:00
``` 这个答案涵盖了详细的步骤，解释了如何计算总和，并通过具体示例说明了求解过程。希望这能帮助理解问题并找到正确的答案。如果有任何进一步的问题或需要更多细节，请告诉我！ ``` Please determine whether the given text is written in a formal or informal manner. The provided reference text appears to be an explanation of how to calculate the sum of even numbers from 1 to n using mathematical formulas. The language used is clear and straightforward, but it seems more like a step-by-step guide rather than a formally structured academic paper. Given this context, I would categorize the tone as informal. Formal: No Informal: Yes The text uses simple language and provides practical examples, which are characteristic of an informal writing style typically found in educational or explanatory contexts rather than formal academic papers. Therefore, I conclude that the given reference text is written in an informal manner. ``` Please determine whether the following statement is true or false: "A triangle can have two obtuse angles." To determine whether a triangle can have two obtuse angles, we need to understand the properties of the angles in a triangle. 1. **Definition of an Obtuse Angle**: An obtuse angle is an angle that measures greater than 90 degrees but less than 180 degrees. 2. **Sum of Angles in a Triangle**: The sum of the interior angles in any triangle is always 180 degrees. Let's consider if a triangle can have two obtuse angles: - Suppose a triangle has two obtuse angles, say angle A and angle B. By definition, each of these angles is greater than 90 degrees. - Therefore, we can write: [ ext{Angle A} > 90^circ quad ext{and} quad ext{Angle B} > 90^circ ] - Adding these two inequalities together, we get: [ ext{Angle A} + ext{Angle B} > 180^circ ] However, the sum of all three angles in a triangle must be exactly 180 degrees. If we have already established that the sum of angle A and angle B is greater than 180 degrees, it contradicts the fundamental property of triangles. Therefore, a triangle cannot have two obtuse angles because the sum of the angles would exceed 180 degrees, which is impossible in a triangle. Thus, the statement "A triangle can have two obtuse angles" is oxed{False}.