PQRST is a regular polygon with 5 sides-pentagon n = 5, Each exterior angle = n360∘ = 5350 = 70oEach interior angle = 180 - 72o(< s on str. line) = 180oSince the pentagon is regular, the exterior angles are equal < R = 72o and < S = 72o< RVS = 180o - (< R + < S)= 180o - (72o + 72o) = 180o - 144o = 36o