Question

can anyone answer the 30th question?​

Answer 1

area of shaded region is 57 cm sq.

Answer 2

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Answer: 57 cm²

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Good question.

The four are semicircles, but I confused because the semicircles in the figure are not actually semicircles!!! We can find it even at first sight!

So the original figure is attached to the answer.

I'm explaining according to my figure.

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First find the area of one such semicircle in the figure and take its double, which means to find the area of the circle having the side of the square as diameter. I'm finding this here.

If this area is subtracted from the area of the square, we get double of area of one such non-shaded part indicated either as a, b, c, d.

When we take the double of this area, we get the sum of areas of the non-shaded parts (a + b + c + d).

So when this is subtracted from the area of the square, we get the shaded region.

So this is the concept I'm using here. If any doubts, please ask me in the 'comments' section.

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Okay, let's start.

Area of the square = 10² = 100 cm².

Area of the circle having side of the square as diameter

= π × (10 / 2)²

= π × 5²

= 25π cm²

Difference of the area of the circle from that of the square

= 100 - 25π

= 25(4 - π) cm²

Twice of the difference

= 2 × 25(4 - π)

= 50(4 - π) cm²

So this is the sum of areas of the non-shaded region.

By subtracting this from the area of the square, we get the answer.

∴ 100 - 50(4 - π)

= 50(2 - (4 - π))

= 50(2 - 4 + π)

= 50(π - 2) cm²

By using π = 3.14,

50(3.14 - 2)

= 50 × 1.14

= 57 cm²

So the answer is 57 cm².

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Hope this may be helpful.

Please mark my answer as the brainliest if this may be helpful.

If any doubt, please don't forget to ask me. And I'll be able to clear it.

Thank you. Have a nice day. :-))

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#adithyasajeevan

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