Question

Find measure angle b -measure angle c if measure angle a of parallelogram abcd is 40°

Answer 1

Given angle a = 40
since opportunity angles of a llgm are equal
so angle a = angle c
angle c = 40

Now Angle a + angle b = 180
( co interior angles )
angle b = 140
and since angle b = angle d
( OPP angles )
angle d = 140

Thus angle a = angle c = 40
angle b = angle d = 140

Hope It Helps.....

Answer 2

angle a is equal to angle c as opposed angles of a parallelogram are equal then
40+40+b+d=360 angle sum ppty of a parallelogram then 40 plus 40 plus b plus b is equal to 360
then B=140
angle b minus angle c is equal to 100
hope this helps u