Which polygon has an interior angle sum of 900°

Read the article about the fraser river, one of the most important rivers in canada. what is the most important species of fish in this river? why are the numbers of these fish declining?

All of the following are extrusive landforms except           a. batholiths.   b. lava plateaus.   c. shield volcanoes.   d. geysers.  

Name the peninsula that separates the bering sea from the sea of okhotsk?