Geometry Lesson 7 7 Scale Drawings and Models

Geometry Lesson 7 – 7 Scale Drawings and Models Objective: Interpret scale models. Use scale factor to solve problems.

Scale Model or Scale Drawing Scale l The scale of a model or drawing is the ratio of a length on the model or drawing to the actual length of the object being modeled or drawn.

The scale on the map shown is 0. 4 inch : 40 miles. Find the actual distance from Nashville to Memphis. Use a ruler to measure 0. 4 x = 60 x = 150 The distance from Nashville to Memphis is 150 miles.

Find the distance from Nashville to Chattanooga. 87. 5 miles

This is a miniature replica of a 1923 Checker Cab. The length of the model is 6. 5 inches. The actual length of the car was 13 feet. What is the scale of the model? Scale is 1 in : 2 ft How many times as long as the actual car is the model? Get the ratio into the same units The scale model is 1/24 as long as the actual car.

Suppose you want to build a model of the St. Louis Arch that is no more than 11 inches tall. Choose an appropriate scale and use it to determine the height of the model. Use the information at the left. The actual model is 630 feet. An approximate model could be 1 in: 60 ft. 630 = 60 x 10. 5 = x So the height of the model would be 10. 5 inches.

Sonya is making a scale drawing of her room on an 8. 5 -by-11 -inch sheet of paper. If her room is 14 feet by 12 feet, find an appropriate scale for the drawing and determine the dimensions of the drawing. 14 feet / 8. 5 inches = Approximately 1. 6 feet per in An appropriate model would be 1 in: 1. 5 ft. The dimensions of the drawing would be : 14 = 1. 5 x x is appx. 9. 3 12 = 1. 5 x 8=x

Homework Pg. 514 1 – 4 all, 6 – 16 E, 26 – 48 E