Answer:
Triangle rsu = Triangle tus
Statements Reasons
UR ≅ TS Definition of Rectangle
US ≅ US Reflexive Property
<U, <T, <R, <S are all congruent and right angles
Definition of Rectangle
ΔRSU ≅ ΔTUS Side, Angle, Side
UR ≅ TS CPCTC
Just draw a reverse angle,hence you get comparison.
So, satisfying S-S-S
RUS ≅ SUT
RSU ≅ TUS
So, angle
URS = angle TUS
2. Pythagoras Theorem
Triangle RUS
A^2 + B^2 = C^2
Uu^2 + Ss^2 = Rr^2
√Rr = Rr^2 = x
Triangle TUS
A^2 + B^2 = C^2
Ss^2 + Uu^2 = Tt^2
√Tt = Tt^2 = x
UR measure / sin (60) x (90) = US measure.
ST measure / sin (60) x (90) = US measure.
Proves angles RSU = 30 degree
Proves angles TUS = 30 degree
As all adjacent angles in a triangle add up to 180 degree.