Watch and take Cornell Notes on the following videos
VIDEO #1 Proportions with Word Problems
http://www.virtualnerd.com/pre-algebra/ratios-proportions/proportionality/solving-proportions/proportion-word-problem-set-up
VIDEO #2 What is a scale drawing?
http://www.virtualnerd.com/pre-algebra/ratios-proportions/scale-models/scale-model-examples/scale-drawing-definition
VIDEO #3 Missing sides of scale/proportional drawings
http://www.virtualnerd.com/pre-algebra/ratios-proportions/similar-figures-indirect-measurement/indirect-measurement/indirect-measurement-example