1. Right-angled.

Nuttall's Standard dictionary of the English language By Nuttall, P.Austin

• rectngular,
• rectanguar,
• rectanglar,
• regtangular,
• rectangualr,
• retangular,
• rectangluar,
• recetangular,
• rectagular,
• rectanular,
• rectanglear,
• rectanguler,
• rectuangular,
• rectangeler,
• rectangler,
• recangular,
• rectangule,
• rectangulare,
• ractangular,
• rectanglular

• reactant,
• reactance,
• rectangle,
• rectangularity.

The adjective form of the word "rectangular" is "rectangular".

The plural form of the word "rectangular" is "rectangulars".

The singular form of the word "rectangular" is "rectangle"