RSTU is a parallelogram. If m∠SRV = 48° and m∠SVR = 54°, explain how you can find the measure of ∠TUV. Show all steps of your work, and refer to any properties of triangles, parallelograms, or triangle congruency theorems as necessary to justify your response. This is from an assignment I submitted earlier. It has not been graded yet, so I just want some input on my response:

It is given that RSTU is a parallelogram. A property of parallelograms is that their opposite sides are parallel, so it's helpful to think of the sides as parallel lines and the diagonals as transversals. To find the measure of ∠TUV, it must be proven that two triangles are congruent. The SSS, SAS, ASA, and AAS postulates can be used to prove that triangles are congruent. Given the circumstances, I will use the AAS postulate to prove triangle SVR congruent to triangle TVU. Another property of parallelograms is that their opposite sides are congruent. So, segment RS is congruent to segment TU. By the Vertical Angles Theorem, ∠SVR is congruent to ∠TVU. So far, there is one side and one angle proven to be congruent. We only need one more congruent angle to prove that the triangles are congruent by AAS. By the Alternate Interior Angles Theorem, ∠SRV is congruent to ∠UTV. Triangle SVR is congruent to triangle TVU by the AAS postulate. Because ∠UTV is congruent to ∠SRV, ∠UTV is 48 degrees. Because ∠TVU is congruent to ∠SVR, ∠TVU is 54 degrees. The Triangle Sum Theorem says that all 3 of a triangle's angles must add up to 180 degrees. 48 degrees + 54 degrees = 102 degrees. 102 must be subtracted from 180 to find the measure of the third angle, TUV. 180 - 102 = 78 degrees. ∠TUV = 78 degrees.