hitung luas lingkaran d=40cm

[tex]\pi \times r \times r[/tex]
3,14 x (40:2) x (40:2)
3,14 x 20 x 20
3,14 x 400
314 x 4
1.256

d = 40 cm
r = d/2 = 40/2 = 20 cm

Penyelesaian:
L = π x r²
L = 3,14 x 20²
L = 3,14 x 400
L = 1256 cm²