Tolong jawab no.4 dan 5 bsk dikumpul

A. L.juring = sudutAOB/360° x L.O
90°/360° x phi.r²
40° x 3,14.12²
18,086.4 cm²
B. L.tembereng = L.juring AOB - L.Segitiga
L.tembereng = 18,086.4 - phi.r²
18,086.4 - 452.16
= 17,364.24 cm²