Answer:
angle A = 166 degrees
Explanation:
so first you have to look at the problem and see what type of relationship the angles have. so if you draw it out yourself, it makes it a little easier and you can see that the two angles are corresponding angles, which means theyre both congruent or, equal.
after you find that out you can set up an equation so,
7x + 40 = 3x + 112
you do the math...
4x + 40 = 112
4x = 72
x = 18
but you cant stop here, you have to plug in x to find teh entire angle A
7 (18) + 40 = ?
126 + 40
166
bam.