甲烷是一种无色、无味、密度比空气小、难溶于水的气体。请阅读有关甲烷材料,完成下列各题:
等腰三角形的一个角是50°,则它一腰上的高与底边的夹角是( )
I____ ____ ____ pick her up, but I was busy with work and forgot it.