Question

Tolong d bantu ya dpt poin bnyk ko nmr 1 A & B ya mkshhhhhh:)

Answer 1

1a
keliling = phi x diameter
keliling = 3,14 x (12x2)
keliling = 3,14 x 24
keliling = 75,36 cm

luas = phi x r²
luas = 3,14 x 12²
luas = 3,14 x 144
luas = 452,16 cm²

1b
keliling = phi x diameter
keliling = 22/7 x 21
keliling = 22 x 3
keliling = 66 cm

luas = phi x r²
luas = 22/7 x (21:2)²
luas = 22/7 x 10,5²
luas = 22/7 x 110,25
luas = 346,5 cm²