What is the least number of sides the cross-section can have?

Find the equation of the line passing through the point (–1, 5) and perpendicular to the line 3x + y = 4.

Dubai is challenged by all of the following environmental factors except a. a warm and dry climate b. a lack of annual rainfall c. scarce freshwater resources d. a lack of valuable natural resources

Who developed the theory of plate tectonics?