A rope of which a calf is tied is increased from 10 m to 20 m, how much additional grassy ground shall it graze? Choose the correct choice from the following options:
A) 540
B) 128
C) 100
D) 942
E) 942.86
π (202 – 102) = 942.86   Answer: 942.86
<result>E</result>
A rope of which a calf is tied is increased from 10 m to 20 m, how much additional grassy ground shall it graze?