East Malaysia is 50% bigger than Peninsular Malaysia at , comparable with South Dakota or Great Britain. East Malaysia contains the five highest mountains in Malaysia, the highest being Mount Kinabalu at 4095 m, which is also the highest mountain in Borneo and the 10th highest mountain peak in Southeast Asia. It also contains the two longest rivers in Malaysia – Rajang River and Kinabatangan River. Banggi Island in Sabah and Bruit Island in Sarawak are the two largest islands that are located entirely within Malaysia. The largest island is Borneo, which is shared with Indonesia and Brunei. The second largest island
Geography of Malaysia districts. There are separate subdivisions for electoral districts for polling purposes. International borders between Malaysia and Indonesia, Thailand, Singapore and Brunei are defined mostly by geological features such as the Perlis River and Golok River between Malaysia and Thailand; Straits of Johor between Malaysia and Singapore; and Pagalayan Canal between Malaysia and Brunei. However, borders that extends to the seas are defined by agreements such as Straits Settlement and Johore Territorial Waters Agreement of 1927 which defines Malaysia and Singapore water borders. Malaysia's land borders are well established. The border with Thailand was established in 1909 when Siam ceded Kedah,