Sorry Guys, Angle 12 & 10 are effectively corresponding angles, but angle 10 & 7 are alternate interior angles. Anyways, Angle 12 & 10 are congruent and 10 & 7 are congruent. At the end, the three angles 12, 10, and 7 have the same measure. If we put it otherwise, the line B is intersecting line D which form right angles equals to 90 degrees, so angle 12 = 90, and the same happens with angle 10 and 7, so the three angles are congruent, but at the same time, angle 7 is supplementary with angle 12 because their sum is equal to 180, (90 + 90 = 180). If you think from different angles is hard to choose the right answer, so what I guess is that we don't need to take into account the angle 10, just the fact that line A intersect line C, and Line B intersect line D forming right angles, and that angle 7 and 12 are right angles which sum equals 180, therefore, we could say that they are supplementary angles, but also congruent because they measure the same, so at the end, I don't know what answer to choose. Both seems correct to me.

d

Step-by-step explanation:Angle 12 & 10 are effectively corresponding angles, but angle 10 & 7 are alternate interior angles. Anyways, Angle 12 & 10 are congruent and 10 & 7 are congruent. At the end, the three angles 12, 10, and 7 have the same measure. If we put it otherwise, the line B is intersecting line D which form right angles equals to 90 degrees, so angle 12 = 90, and the same happens with angle 10 and 7, so the three angles are congruent, but at the same time, angle 7 is supplementary with angle 12 because their sum is equal to 180, (90 + 90 = 180). If you think from different angles is hard to choose the right answer, so what I guess is that we don't need to take into account the angle 10, just the fact that line A intersect line C, and Line B intersect line D forming right angles, and that angle 7 and 12 are right angles which sum equals 180, therefore, we could say that they are supplementary angles, but also congruent because they measure the same, so at the end,

step-by-step explanation:

my answer is$ 12

step-by-step explanation:

because 15 -2=12