Since the two triangles are congruent, they have the same measure of side lengths as well as interior angles.
If ∠UPI is 38o, by the property of congruency, ∠DSA is also 38o.
It is also given that triangle, △DAS is an isosceles triangle as the sides DA and DS are equal.
∴∠DAS=∠DSA
⇒∠DAS=38o
Also, in any triangle the sum of all 3 interior angles is equal to 180 degree.
∴38o+38o+∠ADS=180o
So, ∠ADS=104o.