Question

The length of a minute hand of a clock is 15cm .if the minute hand moves for 20minutes on a circular dial of a clock the area covered by it is -------- cm²

Answer 1

r=15cm

In 1 minute, minute hand covers 6 degrees

So in 20 minute it will cover 20×6=120 degrees

Theta =120

Area covered by minute hand = theta /360×pi×r×r

120/360×22/7×15×15

=110×15/7

=235.71cm square