Question

a wire when bent in the form of a square encloses an area of 484 CM square if the wire is bent in the form of a circle find the area of circle

Answer 1

side of square = √area
=√ 484= 22 cm
perimeter of square = 4× side
=4×22 = 88cm
now
circumference of circle = perimeter of square = 88 cm
or
$2\pi \: r \: = \: 88$

now
r = (88×7)÷ (2×22)
r = 14 cm
now area = pi × r ^2
= (22×14×14)÷7
= 22×2×14
=44×14
= 616 sq cm

Answer 2

✰ ᴜɴᴅᴇʀsᴛᴀɴᴅɪɴɢ ᴛʜᴇ ǫᴜᴇsᴛɪᴏɴ :

A metal wire is first bent into a square shape and had a area of 484 cm² .Next, the same wire is rebent into a circle shape. We have to find the radius and area of the circle and then we should find the length of the wire .

✰ɢɪᴠᴇɴ:

Area of the square = 484 cm²

✰ᴛᴏ ғɪɴᴅ:

length of the wire

radius of the circle

area of the circle

✰sᴏʟᴜᴛɪᴏɴ:

☛Length of the wire :

Let the side of the square be x

given that

➠Area of the square = 484 cm²

➠x² = 484 cm²

➠x = √484 cm²

➠$\boxed{\sf{x = 22 cm }}$

✰ɴᴏᴛᴇ:

As the same wire is bent into square and then into circle ,

length of the wire = Perimeter of the square = circumference of the circle

➠Perimeter of the square

➠4x

➠4(22)

➠88cm

therefore,

$\boxed{\sf{length of the wire = 88cm }}$

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☛Radius of the circle :

circumference of the circle = Perimeter of the square

➠2πr = 88

➠πr = 44

➠r = 44 × (7/22)

➠r = 2 × 7

➠r = 14 cm

$\boxed{\sf{Radius of the circle= 14 cm}}$

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☛Area of the circle:

➠area of the circle

➠πr² cm²

➠(22/7) × 14 × 14

➠44 × 14

➠616 cm²

$\boxed{\sf{area of the circle= 616cm² }}$

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✰ʀᴇʟᴀᴛᴇᴅ ғᴏʀᴍᴜʟᴀ:

SQUARE :

❏Perimeter= 4a units

❏Area = a² sq.units

❏Volume = a³ cu.units

CIRCLE :

❏Circumference = 2πr units

❏Area = π r² sq.units