Tolong bgt no 25 pakai cara pliss

Dik : d = 10 cm
r = d/2 = 10/2 = 5cm
pnjang = 12 cm

Dit = Keliling yg diarsir = ..... ?

Jawab :

Keliling yg diarsir = ( 2 panjang ) + ( 2 d ) + ( 2 panjang busur O )

= ( 2 × 12 ) + (2 ×10 ) + ( 2 ( 180 / 360 × 2 phi r )
= 24 + 20 + 2 ( 1/2 × 2 × 3,14 × 5 )
= 44 + 2 ( 15, 7 )
= 44 + 31,4
= 75,4 cm^2

smoga mmbantu☺
Jadikan yg trbaik yah