翻译：In the xy-coordinate plane,how many points are a distance of 4 units from the origin?

翻译：In the xy-coordinate plane,how many points are a distance of 4 units from the origin? In,the,class.翻译. in the future翻译 in the classics 翻译 in the past翻译 thesis on phase transiions in the two-dimensional,frustrated XY model 求专业人士帮忙翻译下主要是frustrated XY model这个很不理解. in the end翻译in the end翻译in the end翻译in the end翻译in the end翻译in the end翻译 seasons in the sun翻译 In the form of翻译 翻译in the family way in the pop world翻译 in the park(翻译中文 ) in the garden 求翻译 in one of the翻译 in the ring怎么翻译? in the circle如何翻译? in the final analyze翻译 in the very beginning 翻译