Question

the length of the minute hand of a clock is 3.5 cm find the area swept by minute hand in 13 minutes

Answer 1

$<b >Hey here is your answer$

$<color ><red ><marquee> Points to remember to solve the question :- </marquee>$

(1) The minute hand of the clock makes a whole circle when it complete a round and in one round there are 60 minutes total .

It means that the minute hand covers a whole circle in 60 min.

In 1 minute it completes 1/60 part of the circle.

Now, in 13 minutes it complete 13 × 1/60 = 13/60 part of the whole circle .

NOW,

$<marquee> Lets comes to answer :- </marquee>$

GIVEN :-
Radius of the circle (length of the needle) :- 3.5 cm
part of the triangle :- 13/60 part
area of circle :- πr²

$= \frac{22}{7} \times 3.5 \times 3.5$

This answer will found the area of the whole circle but according to 13 minutes we have to find the area of 13/60th part of the triangle so , we have to multiply by 13/60.

NOW,

$\frac{22}{7} \times 3.5 \times 3.5 \times \frac{13}{60} \\ \\ = \frac{3503.5}{420} \\ \\ \bf = 8.341666666......... cm^2 answer \\ \\ or \\ \\ \bf 8.3417 cm^2 answer$

hope this helps you

Answer 2

Find the radius:

Radius = Length of the minute hand

Radius = 3.5 cm

Find the area of the clock:

Area = πr²

Area = π(3.5)² = 38.5 cm²

Find the area swept by minute hand in 13 minutes:

Area = 13/60 x 38.5 = 8.34 cm²

Answer: Area = 8.34 cm²