If you use a scale factor of 1/5 to create a circle with radius 18 cm, what is the radius of the original circle you dilated?(1 point) Responses 90 cm 90 cm 180 cm 180 cm 9 m 9 m 3.6 cm

Answer 1

To find the radius of the original circle before dilation, you can use the scale factor. The scale factor of 1/5 means that the original circle's dimensions are 5 times larger than the dilated dimensions.

The radius of the dilated circle is 18 cm. Using the scale factor:

\[ \text{Original radius} = \text{Dilated radius} \times \text{Scale factor's denominator} \] \[ \text{Original radius} = 18 , \text{cm} \times 5 = 90 , \text{cm} \]

Therefore, the radius of the original circle is 90 cm.