Could someone pplz plz with this problem

12.

So we can assume straight angles, and straight angles are 180 degrees.  It is a bit hard to explain without the names of the angles but I will try my best.

We know the angle with the measure of 100 is part of a straight angle, so if you do:
180-100 = 80

We know the highest vertex of the triangle in the middle has the angle of 80 now, again, because it is supplementary to the angle with the measure of 100.

Then we do the same for the angles with the mesure of 92.
180- 92 =88.

So we know the angle on the left side of the triangle has a measure of 88.

Then we have 2 angles of a triangle, and we know all angles of a triangle add up to 180.  So we do:
180- (88+80) = 12

Then we have the last angle, the angle at the right side of the triangle.  Then we know vertical angles are congruent.  So x is 12.

Hope this can help you! Please give me the brainliest answer if you like it! If you have other questions, please leave a comment or add me as a friend! 

X=12. I am good at math, but I'm not good at explaining it.

A=l×wa=(8x+6) (13x+11)a=104x➋+166x+66