tolong jawabkan nomor 4

Luas tembereng AOB = Luas juring - Luas Segitiga
Lt =(120/360 x L O) - ( 1/2 x a x t )
    = (1/3 x πr²) - (1/2 x 10 x (t² = 7² - 5²)
    = (1/3 x 22/7 . 7²) - (1/2 x 10 x 2√6)
    = (1/3 x 22/7.49 ) - ( 5 x 2√6)
    = 51,333 - 5 x 2√6
Lt = 46,333 x 2√6  cm²