Scale Factor

What Is Scale Factor?

Scale factor is the ratio of the length of the scale drawing to the corresponding length of the original object.

Solving Problems

We are told to find the scale factor when we are given the original and new dimension of an object. The formula for questions like these are : Original dimension(x) = New dimension. X is equal to the unknown scale factor. In this first example, we are told to find the scale factor and the original dimension is 2", while the new dimension is 1/8". Using the formula we just learned, we can find the unknown scale factor by plugging in the numbers into the formula. The equation becomes 2x = 1/8. To get 'x' by itself, also known as isolating the variable, we divide 2 by 2 and 1/8 ÷ 2, which is 1/16. We discover that x = 1/16. This isn't our final answer. Scale factors are written as ratios, so the final answer could be written as 1/16 : 1 or 1:16 .

Solving Problems

In this final example, we are told to find the new dimension when we are given the original dimension and scale factor. The formula used to solve this question is : Original dimension • First number in scale factor = New dimension. The original dimension is 1/8" and the scale factor is 2:1. We multiply 1/8 · 2, which equals 2/8 and when simplified, 1/4. The answer is 1/4"