tolong dijawab beserta caranya masing-masing....

3]

K = 2 x 3,14 x 20
K = 6,28 x 20
K = 125,6 cm → opsi A


4]

L = π x r²

L = 22/7 x 14²

L = 22/7 x 196

L = 616 cm² → opsi D



6]

Luas Arsiran :

= (a/360) x luas lingkaran
= (90/360) x 3,14 x 10²
= (1/4) x 314
= 78,5 cm²


7] Luas arsiran

= Luas ½ besar - Luas ½ kecil
= (½ x 22/7 x 7²) - (½ x 22/7 x 3,5²)
= 77- 19,25
= 57,75 cm²