Question

solve question no.11 and 12​

Answer 1

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★ radius of circle = 21 m.

Now we have to find the area of circle, so as we know that the area of the circle is given by,

→ Area = πr²

→ Area = 22/7 × (21)²

→ Area = 22/7 × 21 × 21

→ Area = 22 × 21 × 3

→ Area = 63mutiplied 22

1386 is answer

Answer 2

[ 1 ]

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GIVEN :-

• radius of Circle , r = 21 m

TO FIND :-

• The area of Circle.

SOLUTION :-

➳ Area of Circle = πr²

➳ Area of Circle = 22/7 × (21)²

➳ Area of Circle = (22 × 441)/7

➳ Area of Circle = 9702/7

➳ Area of Circle = 1386.

Hence the area of Circle is 1386 m².

[ 2 ]

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GIVEN :-

• Two concentric circles have radii of 14 cm and 7 cm.

TO FIND :-

• The area of space between them.

SOLUTION :-

Let the radius of smaller circle be "r" and the radius of bigger circle be "R"

➳ Area = πR² - πr²

➳ Area = π(R² - r²)

➳ Area = 22/7 (14² - 7²)

➳ Area = 22/7 (14 × 14 - 7 × 7)

➳ Area = 22/7 (196 - 49)

➳ Area = 22/7 × 147

➳ Area = 462 cm².

Hence The area of space between them is 462 cm².