tolong bantu kak bagaimana caranya

Luas juring AOB - Luas Juring DOC
60/360 π (7²) - 60/360 π (3,5²)
1/6 π (7² - 3,5²)
1/6 π (49 - 12,25)
1/6 π (36,75)
1/6 (22/7) (36,75)
808,5/42
19,25 cm