Enlarging a Shape with a Fractional Scale FactorA shape can be enlarged with a scale factor. Usually, this makes the shape larger. If the scale factor is a fraction (between 0 and 1), the enlargement makes the shape smaller.
How to Enlarge a Shape with a Fractional Scale FactorEnlarging a shape with a fractional scale factor is easy.
QuestionEnlarge the shape below by a scale factor of 1⁄3 about the centre of enlargement (1, 1).
Draw a line from the centre of enlargement to point A.Note: It is useful to extend the line beyond the point.
Measure the length of this line. In our example, the point is 3 diagonal units from the centre of enlargement (or 3 units across and 3 up).
Multiply this distance (3) by the scale factor (1⁄3).The distance to the transformed point is 1 diagonal unit (or 1 unit across and 1 up).
Scaled distance = Distance × Scale factor
Scaled distance = 3 diagonal units × 1⁄3
Scaled distance = 1 diagonal unit
Measure the distance found in Step 4 along the line drawn in Step 2. This is the point on the enlarged shape, which we will call A'.
Answer:With all the vertices (corners) of the shape transformed, the enlarged shape can be drawn:
By multiplying the shape by a scale factor of 1⁄3, the enlarged shape is a 1⁄3 of the size and a 1⁄3 the distance from the centre of enlargement.