Multiply each dimension by the scale factor:
9 x 12 → (9 x 2.5) x (12 x 2.5) = 22.5 x 30
12
12
12
Convert to same units, then can cancel out units: 1 ft = 12 in → 1 in : 4 ft = 1 in : 4 x 12 in = 1 in : 48 in = 1 : 48 So the scale factor is 48.
Having sex
12
12
Assuming the smaller sphere is the image of the larger sphere after transformation (based on the order of the radii): the scale factor is 4/12 = 1/3
It is: 21/12 = 7/4
It is: 3 to 2
It is: 2 to 3
12
It is: 2 to 3
To find the new area, you have to multiply the original area by the square of the scale change. For example, you have a rectangle with adjacent sides of 3 and 4. Another rectangle has the same dimensions but with triple the scale. The original rectangle's area is 12. Multiply that by 9, which is the square of the new scale, and you get an area of 108. That matches up with the area of the new rectangle, which has adjacent sides of 12 and 9.
When a rectangle measuring 8 cm by 3 cm is dilated by a scale factor of 4, each dimension is multiplied by 4. This means the new length will be 8 cm × 4 = 32 cm, and the new width will be 3 cm × 4 = 12 cm. Consequently, the dilated rectangle will have dimensions of 32 cm by 12 cm.
Convert to same units, then can cancel out units: 1 ft = 12 in → 1 in : 4 ft = 1 in : 4 x 12 in = 1 in : 48 in = 1 : 48 So the scale factor is 48.
12r = p