趣味数学题04 | 三角形求角度数问题 - 趣味数学题

请问下图中$x$的度数是多少？

解：

$$\begin{align}&\because a=180^{\circ}-(30^{\circ}+120^{\circ})=30^\circ \\ &\therefore b=\frac{180^\circ-a}{2}=75^\circ \\ &\therefore x=180^\circ-30^\circ-(180^\circ-b)=45^\circ \end{align} $$

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趣味数学题04 | 三角形求角度数问题