这个正方形的边长是6厘米<img src="https://iknow-pic.cdn.bcebos.com/279759ee3d6d55fb3ec9eac56d224f4a21a4ddc2?x-bce-process=image/resize,m_lfit,w_600,h_800,limit_1" max-height="200">周长是6×4=24厘米