The sum of the angles in a parallelogram is 360°.
a+b+c+d=360°
The opposite angles in the parallelogram are congruent.
a=c
b=d
So if a=24°... and we know a=c, then c=24°.
a=24
c=24
b=?
d=?
a+b+c+d=360°
plug in the data we know
24+b+24+d=360
48+b+d=360
b+d=312
If b+d=312, and we know that they are congruent, then to find their values just divide 312 by 2
312/2=156°
b=156°
d=156°
