document.write( "Question 242792: Always, sometimes, or never; If the opposite angles of a quadrilateral are supplementary, the quadrilateral is a parallelogram \n" ); document.write( "
Algebra.Com's Answer #177752 by Edwin McCravy(20060)![]() ![]() You can put this solution on YOUR website! Always, sometimes, or never; If the opposite angles of a quadrilateral are supplementary, the quadrilateral is a parallelogram. \n" ); document.write( " \r\n" ); document.write( "When and only when the quadrilateral is a parallelogram which is also \r\n" ); document.write( "a rectangle and the opposite angles are both 90°. Two right angles\r\n" ); document.write( "are supplementary.\r\n" ); document.write( "\r\n" ); document.write( "\n" ); document.write( " |