Answer:
b=100
a=80
c=100
Explanation:
to find b we know that in a straight angle there is 180 degrees and since we already know that one side is 80 degrees we just need to substract 180 by 80 to get 100 degrees.
since its parallel lines we can confirm that 80degrees and r are coresponding angles so r=80.Which also means a and r are alternate angles so a=80.
Lastly to find c we need to do the same thing as we did with b. Which means c=100