Western Australia has a land area of 2,525,500 sq km, almost one third of Australia.
The UK has a land area of 243,609 sq km.
The UK will fit into Western Australia about 10.4 times.
The area of Western Australia is 2,525,500 sq km while the area of South Africa is 1,221,037 sq km. Therefore, South Africa would fit into Western Australia just over twice (2.068 times).