Answer: b=90,d=100,c=80
Explanation:
A parallelogram's interior angles have an interesting property.
Two adjoining angles add up to 180 degrees.
Therefore, we can find that d+b-10=180
d+b=190
next, let's use the same property again to find b
b-10+b+10=2b=180
Therefore, b = 90
Now let's set up the equation for c.
b+10+c=180
b+c=170
90+c=170
c=80
d+b=190
d+90=190
d=100
Therefore, b=90,d=100,c=80