Question

The measure of an angle of a parallelogram is 12 degrees less than 3 times the measure of an adjacent angle. find the measure of all the interior angels of the parallelogram.

Answer 1

"adjacent" angles of a parallelogram add up to 180°.

so let one angle be x
then the adjacent is 3x-12

solve for x

x + 3x-12 = 180

So now you have a pair of adjacent angles, take it from there.

Answer 2

x=48

Answer 3

x=42