Please help I will give brainliest

100°

Step-by-step explanation:

First, remember that flat angles are always 180°,

So the angle of B is 40° because they form that kind of angle.

Now, you can notice that both sides of the triangle have the same value.

That means the angle is the same too.

So, the third angle is also 40°

Last but not least the addition of all angles in a triangle is always 180°

With that in mind we just solve the next equation:

40° + 40° + a° = 180

a° = |80 - 80

a = 100°

And that is how we find the answer, hope it was helpful ;)

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.