you use scale factor of 2/3 to create a dilated circle with a radius of 10 inches. What is the radius of the original circle?

1 answer

To find the radius of the original circle when a dilated circle has a radius of 10 inches and a scale factor of \( \frac{2}{3} \), you can use the formula for dilation:

\[ \text{Radius of the original circle} = \frac{\text{Radius of the dilated circle}}{\text{Scale factor}} \]

Substituting the known values:

\[ \text{Radius of the original circle} = \frac{10 , \text{inches}}{\frac{2}{3}} \]

Dividing by a fraction is the same as multiplying by its reciprocal:

\[ \text{Radius of the original circle} = 10 , \text{inches} \times \frac{3}{2} = 15 , \text{inches} \]

Thus, the radius of the original circle is \( 15 , \text{inches} \).