Understand Scale and Proportions in Geometry

Front

What is a scale in geometry?

Back

A scale is a ratio that compares a measurement on a drawing or model to the actual measurement of the object.

Front

If the scale is 1 inch = 7 feet, how do you convert feet to inches?

Back

Multiply the number of feet by the scale factor (1 inch/7 feet).

Front

What is the formula to find the new perimeter when enlarging a shape by a scale factor?

Back

New Perimeter = Original Perimeter × Scale Factor.

Front

If a model is 2 ft wide and the scale is 1 foot = 100 yards, how do you find the actual width?

Back

Multiply the model width by the scale factor (2 ft × 100 yards/1 ft = 200 yards).

Front

What does a scale factor of 1/2 mean?

Back

It means the new shape is half the size of the original shape.

Front

How do you find the actual distance represented by a certain length on a map?

Back

Use the scale to convert the map length to actual distance (e.g., if 3 cm = 12 km, then 5 cm = (5 cm × 12 km) / 3 cm).

Front

What is the relationship between scale and proportion?

Back

Scale is a specific type of proportion that relates the dimensions of a model to the actual object.

Front

If a rectangle's perimeter is 30 cm and is enlarged by a scale factor of 4, what is the new perimeter?

Back

New Perimeter = 30 cm × 4 = 120 cm.

Front

What is the actual distance if 5 cm on a map represents 20 km?

Back

5 cm represents 20 km based on the map's scale.

Front

How do you determine the scale factor between two similar shapes?

Back

Divide the dimensions of the new shape by the corresponding dimensions of the original shape.