6.2 – Use Proportions to Solve Geometry Problems

1
6.2 Use Proportions to Solve Geometry Problems
2
6.2 Use Proportions to Solve Geometry Problems

• Example 1
• In the diagram, MN/RS NP/ST. Write four other
  true proportions.

3
6.2 Use Proportions to Solve Geometry Problems

• Example 2
• In the diagram, BD/DA BE/EC. Find BA and BD.

4
6.2 Use Proportions to Solve Geometry Problems

• A scale drawing is a drawing that is the same
  shape as the object it represents.
• The scale is a ratio that describes how the
  dimensions in the drawing are related to the
  actual dimensions of the object.

5
6.2 Use Proportions to Solve Geometry Problems

• Example 3
• The blueprint shows a scale drawing of a cell
  phone. The length of the antenna on the
  blueprint is 5 cm. The actual length of the
  antenna is 2 cm. What is the scale of the
  blueprint?

6
6.2 Use Proportions to Solve Geometry Problems

• Example 4
• The scale of the map at the right is 1 in26
  miles. Find the actual distance from Pocahontas
  to Algona.

7
6.2 Use Proportions to Solve Geometry Problems

• Example 6
• You buy a 3-D scale model of the Reunion Tower is
  Dallas, TX. The actual building is 560 feet
  tall. Your model is 10 inches tall, and the
  diameter of the dome on your scale model is 2.1
  inches.
• What is the diameter of the actual dome?
• About how many times as tall as your model is the
  actual building?