please bantu jawab pelajaran guru KILLER besok harus dikumpulkan!! pakai cara

141 = luas PQRS + luas 2 x 3/4 lingkaran

luas PQRS = p x l = 2r x r

141 = 2r^2 + 3/4 πr^2
141 = 2r^2 + 33/7 r^2
141 = 47/7 r^2
r^2 = 21

luas PQRS = 2r^2 = 2 x 21 = 42