What is the sum of the interior angles of a rectangle?
4°
360°
180°
90°

180

The sum of the angles in a rectangle is given by (n-2)180 where n is the number of sides of the polygon and n is greater than or equal to 3.  For a rectangle, n=4 thus sum of angles is (4–2)180 = 360 degrees. Each interior angle is 360/4 = 90 degrees.

a) one student is chosen from classroom a, then a student is chosen from classroom b.  

step-by-step explanation:

independent events are ones in which the probability of one event does not affect the probability of the second event.

one student is chosen from classroom a; this does not affect the chances of choosing a student from classroom b.   this makes these independent events.

when one card is chosen from a standard deck and then set aside before a second card is chosen, the probability of the second card being chosen changes.   this makes them dependent events.

when one student is chosen from classroom a and then a second student is chosen from classroom a, the probability of choosing the second student changes.   this makes them dependent events.

when a letter is chosen from the alphabet and then a second letter is chosen, the probability of choosing the second letter changes.   this makes them dependent events.