The probability of an event is given by the number of favorable outcomes divided by the total number of outcomes. Here the event is the alarm clock running out of power. There are 24 hours during which the power can go out. You are asleep during 8 of these. A "favorable" outcome in this case is the power going out while you are sleeping -- that is, during one of those 8 hours. This makes the probability that the power goes out while you are sleeping 8/24.
Ok so to find which sides are congruent we need to know their lengths.
To find the length we need the distance formula between two point ->
√(X2-X1)∧2 +(Y2-Y1)∧2
Ok lets find the first side PQ
P(-1,3) Q(2,-1)
X1 Y1 X2 Y2
√(2-(-1)∧2 + (-1-3)∧2 = 5
Now PR
P (-1,3) R (5,3)
X1 Y1 X2 Y2
√(5-(-1))∧2 + (3-3)∧2) = 6
Now the last side QR
Q (2, -1) R (5,3)
X1 Y1 X2 Y2
√(5-2)∧2 + (3-(-1))∧2 = 5
From the above work we see that PQ and QR are congruent becuase they are equal PQ=QR
Also the opposite angles of these sides are congruent. Hope this helps :).
