Typically Bay window is consisted of three Windows joined together. The center window is usually fixed, with operating double-hung or casement Windows at the sides.

典型的弓型窗是由三扇窗组合而成。中间为固定窗，两侧为提拉窗或平开窗。

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Built in 1800, Hank McNeil's Neo-Georgian 13, 000-square-foot Rittenhouse Square mansion is red brick and cube-shaped, with rectangular double-hung windows all aligned and a red front door flanked by Corinthian columns.

WSJ: The House With a Surprise Inside