多选题： A quadrilateral that can be inscribed in a circle is also called a cyclic quadrilateral．Which of these quadrilaterals are always cyclic ． A．parallelograms kites B．isosceles trapezoids C．rhombuses D．rectangles E．squares． 圆内接四边形又称为联圆四边形，下列是联圆四边形的有 A．平行四边形；B．等腰梯形；C．菱形；D．矩形；E．正方形．
题目简介
多选题：Aquadrilateralthatcanbeinscribedinacircleisalsocalledacyclicquadrilateral．Whichofthesequadrilate
题目详情
A quadrilateral that can be inscribed in a circle is also called a cyclic quadrilateral．Which of these quadrilaterals are always cyclic ．
A．parallelograms kites B．isosceles trapezoids C．rhombuses
D．rectangles E．squares．
圆内接四边形又称为联圆四边形，下列是联圆四边形的有
A．平行四边形；B．等腰梯形；C．菱形；D．矩形；E．正方形．
答案
B、等腰梯形在同一底上的两个角相等，则它的对角互补，故是圆内接四边形；
C、菱形的对角相等，不一定互补，故不一定是圆内接四边形；
D、矩形的四个角是直角，即对角互补，故是圆内接四边形；
E、正方形的四个角都是直角，故是圆内接四边形．
故答案为BDE．