What quadrilateral have an obtuse angle

What are potential hypotheses (explanations) regarding why there are ecological equivalents between many metatherians and eutherians? discuss your hypothesis in terms of the processes that could lead to the current ecologies and distributions of metatherians and eutherians.

If angle 2=3x +1 and angle 3=2x +4what is angle 2

If a || b and b | y, then ? a) x || y. b) x | a. c) a | y. d) a || y.