Engineers and architects use proportions all the time in scale drawings. In scale drawings, they compare each length in the drawing to the actual length.
Example: Suppose you want to make a scale drawing of a room with a scale of 1 cm = 50 cm, (1:50). What are the dimensions of a 4.5 m by 6.2 m room?
Width = 9 cm, length = 12 cm
SF05 Similar Figures_Missing Side
SF13 Similar_Triangles 1
SF14 Similar Triangles 2
A scale drawing that is smaller than the original is called a reduction.
A scale drawing that is larger than the original is called an enlargement.
Homework: Draw your bedroom on chart paper, showing basic details (door, windows, etc.). Use the scale one inch is equal to one foot.
Compute square footage, and calculate the costs of carpeting based on square footage.
If students write their own word problems they will learn how word problems are constructed, develop their reasoning skills, and make connections between math concepts and the real world.