2originalstickerWhat type of scale drawing is the sticker?What is the importance of proportionality for Rubin?How could we go about checking for proportionality of these two images?
3Steps to check for proportionality for scale drawing and original object/picture: 1. Measure lengths of scale drawing. Record on table.2. Measure corresponding lengths on actual picture/drawing. Record on table.3. Check for constant of proportionality.
4Key Idea:The scale factor can be calculated from the ratio of any length in the scale drawing to its corresponding length in the actual picture.The scale factor corresponds to the unit rate and the constant of proportionality.Scaling by factors greater than 1 enlarge the segment and scaling by factors less than 1 reduce the segment
5What relationship do you see between the measurements? Is the sticker proportional to theoriginal sketch?How do you know?What is this called?What is the scale factor for the sticker as compared to the original sketch? How do you know?Each of the corresponding lengths are how many times larger?What can you predict about an image that has a scale factor of 3?
6Use a scale factor of 3 to determine the lengths on the new image 1 1/211/21/4
7Is this a reduction or an enlargement? How could you determine even before the drawing?Can you predict what the scale lengths of the scale drawing will be?What steps were used to create this scale drawing?
8Create the drawing with a scale of 1/2 What steps were used to create this scale drawing?
93ft3ftWhat is the shape of the portrait?Will the resulting picture be a reductionor a magnification?What needs to be done before multiplying thescale lengths by the scale factor?What will the scale drawing look like?Give the new lengths in inchesScale Factor 1/18
105 ftFind the new diameter in inchesScale factor 1/30
11Where is the constant of proportionality represented in scale drawings? What step(s) are used to calculate scale factors?What operation(s) is (are) used to create scale drawings?
12Exit Ticket A rectangular pool in your friend’s yard is 150 ft. x 400 ft. Create a scale drawing with a scale factor of 1/600 Use a table or equation to show how you computed your scale drawing lengths.