Question

The minute hand clock of a traces an area 〖51〗1/3 sq.cm in 20 min .Find the length of the minute hand

Answer 1

Answer:

angle/360*πr²=〖51〗1/3

here r is lenght of minute hand

angle made in 20 min is?

12 hrs = 360°

720minutes=360°

divide by 36 on both sides

720/36 minutes=(360/36) °

20 min= 10°

so,

10/360*22/7*r²=〖51〗1/3

11/126 * r²= 154/3

r²=14*32

r=8√7