RSTU is a parallelogram.
What is the measure of ∠UST?

Answer:
[tex]m\angle UST= 95\°[/tex]
Step-by-step explanation:
Givens:
We know that by definition that parallelogram's angles all sum 360°. If we have a diagonal inside, then, we have two triangles, where their angles sum 180°. Also, in this scenario, we have two parallels being crossed by a transversal, which can allow us to deduct several congruences.
So, from the transversal and parallels, we have:
[tex]m\angle RSU = m\angle SUT = 25\°[/tex]; because they are alternate interior angles.
Now, we consider [tex]\triangle SUT[/tex], where we already know two angles [tex]m\angle SUT = 25\°[/tex] and [tex]m\angle STU = 60\°[/tex]. So, internal angles of a triangle sum 180°, using that we calculate the missing angle ∠UST:
[tex]m\angle UST + m\angle SUT + m\angle UTS = 180\°\\m\angle UST=180\° - m\angle SUT - m\angle UTS\\m\angle UST=180\° - 25\° - 60\°\\\therefore m\angle UST= 95\°[/tex]