Sarah wants to build a model of the Golden Gate Bridge for a school project. She decides that her scale model needs to be 1/20th the size of the real bridge. When she looked online, Sarah found that the base of the bridge is 4,200 ft long and 90 ft wide. If she uses a scale of inches to feet, what are the dimensions of her model? What is the scale factor?

Question

Sarah wants to build a model of the Golden Gate Bridge for a school project.  She decides that her scale model needs to be 1/20th the size of the real bridge.  When she looked online, Sarah found that the base of the bridge is 4,200 ft long and 90 ft wide.  If she uses a scale of inches to feet, what are the dimensions of her model?  What is the scale factor?

Reiny · Answer

the real scale model would have a base of 4200/20 ft or 210 ft
by 90/20 or 4.5 ft
She wants to reduce this even further so that 1 inch represents 1 foot
so her model should have a length of 210/12 inches or 17.5 inches
and a width of 4.5/12 or .375 inches, the same as 3/8 of an inch

so 17.5 by 3/8 inches