2-8 Proportions and Similar Figures

Similar Figures: Have the same shape but not necessarily the same size

The measures of corresponding angles are equal, and corresponding side lengths are proportional

The order of the letters when you name the figures is so important because it tells you which parts of the figure are corresponding parts

ABC FGH

Problem 1: Finding the Length of a Side

Problem 2: Applying SimilarityThe sun’s rays strike the building and the girl at the same angle, forming two similar triangles shown. How tall is the building

Scale drawing: a drawing that is similar to an actual object or place

(floor plans, blueprints, maps)

Scale: the ratio of any length on the drawing to the actual length

Problem 3: Interpreting Scale Drawings

What is the actual distance from Jacksonville to Orlando?

Scale Model: a three-dimensional model that is similar to a three-dimensional object

Problem 4: Using Scale ModelsA giant model heart is shown below. The heart is the ideal size for a man who is 170 ft. tall. About what size would you expect the heart of the man who is 6 ft. tall to be?