A line measure 180 what is the measurement of the unknown angle

Determine whether the set of whole numbers is closed under addition. explain why the set is or is not closed. give an example.

Atype of plant is introduced into an ecosystem and quickly begins to take over. a scientist counts the number of plants after mmonths and develops the equation p(m)= 19.3(1.089)^m to model the situation. most recently, the scientist counted 138 plants.assuming there are no limiting factors to the growth of the plants, about how many months have passed since the plants werefirst introduced? a)o 6.1b)0.6.6c)10 72d)o 23.1

Cd is the perpendicular bisector of both xy and st, and cy=20. find xy.