Proportional Geometry Math Example 4

Follow the full solution, then compare it with the other examples linked below.

Example 4

easy
Two similar rectangles have widths 5 cm and 15 cm. What is the scale factor from the smaller to the larger?

Solution

  1. 1
    Step 1: Scale factor =larger dimensionsmaller dimension=155=3= \dfrac{\text{larger dimension}}{\text{smaller dimension}} = \dfrac{15}{5} = 3.

Answer

Scale factor = 3
The scale factor between similar figures is the ratio of any pair of corresponding lengths. Once found, it applies to every pair of corresponding lengths in the two figures.

About Proportional Geometry

Proportional geometry studies how corresponding lengths, areas, and volumes scale between similar figures. If two triangles are similar with scale factor k, their sides are in ratio k, their areas in ratio k², and their volumes in ratio k³.

Learn more about Proportional Geometry →

More Proportional Geometry Examples

Example 1 easy

Two similar triangles have corresponding sides in the ratio 3:5. If the shorter triangle has a base

Example 2 medium

A 6 ft tall person casts a shadow 4 ft long. At the same time, a tree casts a shadow 14 ft long. How

Example 3 medium

Two similar rectangles have widths [formula] cm and [formula] cm. If the smaller rectangle has lengt

Example 5 hard

On a map, 1 cm represents 50 km. Two cities are 3.6 cm apart on the map. What is the actual distance

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