Arizona (USA) is 18% larger than Oregon (USA).
Arizona is a state in the southwestern region of the United States. It is also part of the Western United States and of the Mountain West states. It is the sixth largest and the 15th most populous of the 50 states. Its capital and largest city is Phoenix. Arizona is one of the Four Corners states. Wikipedia
Oregon is a state in the Pacific Northwest of the United States. It is bordered on its west by the Pacific Ocean, north by Washington, south by California, east by Idaho, and southeast by Nevada. The Columbia River delineates much of Oregon's northern boundary, the Snake River largely its eastern. Wikipedia