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Please help! This question is really confusing me!

Please help! This question is really confusing me!-example-1
User Kientux
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1 Answer

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Answer:

The area is the square unit.

Let the scale factor is k.

The unit circle has area of π.

Similar circle is k times the unit circle.

  • r₂/ r₁ = k

The ratio of areas is the square of the scale factor:

  • A₂/A₁ = k²

If the scale factor is r, then the area of the circle with radius of r is:

  • A₂ = A₁k² = A₁r²

Since A₁ = π, the area of A₂ is:

  • A₂ = π*r² = πr²
User Psychoschlumpf
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