Penjelasan dengan langkah-langkah:

luas lingkaran = πr²

a. luas lingkaran = πr²

803,84 = 3,14 x r²

803,84/3,14 = r²

256 = r²

√256 = r

16 cm = r

Diameter = 2xr

diameter = 2 x 16 = 32 cm

b. luas lingkaran = πr²

1386 = 22/7 x r²

1386/ \frac{22}{7}

7

22

= r²

1386 x \frac{7}{22}

22

7

= r²

441 = r²

√441 = r

21 = r

diameter = 42

c. luas lingkaran = πr²

5024 = 3,14 x r²

5024 / 3,14 = r²

1600 = r²

√1600 = r

40 = r

diameter = 80

d. luas lingkaran = πr²

3850 = 22/7 x r²

3850/ \frac{22}{7}

7

22

= r²

3850 x \frac{7}{22}

22

7

= r²

1225 = r²

√ 1225 = r

35 = r

diameter = 70