Question

the ratio of area of a circle to the area of semi-circle is-

Answer 1

$\textbf {Hey there, here is the solution.}$

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Area of circle = πr²

Area of semi-cirlce = 1/2 πr²

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Find the ratio:

Ratio of area of circle : area of semi-circle = πr² : 1/2 πr²

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Simplify:

πr² : 1/2 πr²

Divide by πr² through

1 : 1/2

Multiply by 2:

2 : 1

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Answer: Ratio of area of circle : area of semi-circle = 2 : 1

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$\textbf {Cheers.}$

Answer 2

Heya!

Let radius of full circle be r. Then, Area of full circle = πr² and area of semi-circle (half circle) = (πr²)/(2)......

Now, Ratio of area of circle to area of semi circle $= \pi r^2 : \frac{\pi r^2}2 = \pi r^2 \div \frac{\pi r^2}2 = \pi r^2 \times \frac{2}{\pi r^2} = 2 \: or \: \frac{2}1 \: or \: 2:1$

Hope this helps!