title: Lake Baikal
context: Like Lake Tanganyika, Lake Baikal was formed as an ancient rift valley, having the typical long, crescent shape with a surface area of 31,722km2 (12,248sqmi). Baikal is home to thousands of species of plants and animals, many of which exist nowhere else in the world. The lake was declared a UNESCO World Heritage Site in 1996.[14] It is also home to Buryat tribes who reside on the eastern side of Lake Baikal,[15][16] raising goats, camels, cattle, sheep, and horses,[16] where the mean temperature varies from a winter minimum of −19°C (−2°F) to a summer maximum of 14°C (57°F).[17]
question: What is the surface area of Lake Baikal?
answers.text: 31,722km