Step-by-step explanation:
QU=DA(given)
DU=DU(common)
QD=UA(given)
there they are congruent because of SIDE SIDE SIDE
For every possible angle
, the fundamental law of trigonometric states that

In your case, the inputs you provided would lead to

So, it is not possible that, for a certain angle x, we have

Answer:
Yes by SAS
Step-by-step explanation:
if you do 42 / 18 you see that the relationship between the sides is 2.3333... so that is one proportional side
Then, you see that there is one angle in both triangles that is 76 degrees, so that is one equal angle
then, you can do 21 / 9 = 2.33333... which is the same as the first proportion which means that is another proportional side.
then you have a side, angle, and a side, so it's SAS