Answer:
d. 90°
Step-by-step explanation:
Recall: based on the properties of a kite, the angles where the two unequal sides meet are congruent, this means that m<S = m<U.
Also, the sum of all angles of a kite = 360°
Therefore:
m<S + m<U + m<R + m<T = 360°
m<S = m<U = 80°
m<R = 110°
Substitute
80° + 80° + 110° + m<T = 360°
270° + m<T = 360°
Subtract 270° from each side
m<T = 360° - 270° = 90°
