Frequently, scientists, architects, and other professionals need to calculate the height of objects or distances between objects that cannot be measured directly. Different techniques of indirect measurement can be used.

student asking how tall is Reunion Tower in Dallas and an image of Reunion Tower in Dallas, Texas

Source: Reunion Tower Dallas, texas_mustang, Wikimedia Commons

Santa Elena Canyon and student in canoe asking how wide is the Santa Elena Canyon in Big Bend National Park

Source: Santa Elena Canyon BIBE, R Henley, Wikimedia Commons

Sometimes, a scale factor is used to generate similar figures.

student asking about the scale used to make this model of the Alamo and a scale model of the Alamo

Source: The Alamo Miniature, Schubbay, Wikimedia Commons

In this lesson, you will investigate how properties of similar figures can be used to find the height of objects and to find the scale factors to either reduce or enlarge.