Question

Hitunglah diameter bola jika π = 3,14 dan luas permukaannya adalah :
1. 200,96 cm2
2. 452,16 cm2
3. 1.256 cm2
4. 5.024 cm2

Answer 1

1. L = 4 (x) 3,14 (x) r^2
   200,96 = 4 (x) 3,14 (x) r^2
   200,96 : 12,56 = r^2
   16 = r^2
   4 = r

2. 452,16 = 4 (x) 3,14 (x) r^2
    452,16 : 12,56 = r^2
    36 = r^2
    6 = r

3. 1.256 = 4 (x) 3,14 (x) r^2
    1.256 : 12,56 = r^2
    100 = r^2
     10 = r

4. 5.024 = 4 (x) 3.14 (x) r^2
    5.024 : 12,56 = r^2
    400 = r^2
    20 = r