Scale Factors and Trapezoid Analysis

Mr. Hul introduces lesson 21, focusing on changing scales in scale drawings. He explains why lesson 20 was skipped and dives into an exercise involving trapezoid drawings. The lesson covers calculating scale factors and comparing original and new scale drawings, emphasizing the importance of understanding scale changes.

Why was Lesson 20 not included in the video series?

• The lesson was not part of the curriculum.

• The lesson was too short to be recorded.

• The lesson involved tedious calculations not suitable for video.

• It was a theoretical lesson with no practical application.

What is the main focus of Lesson 21?

• Exploring geometric shapes.

• Understanding algebraic equations.

• Learning about historical mathematicians.

• Exercises on changing scales and scale factors.

In the exercise, what shape was used for the scale drawing?

• Trapezoid

• Triangle

• Rectangle

• Circle

What does a scale factor greater than one indicate?

• A reduction in size.

• A conversion to a different unit.

• An enlargement of the drawing.

• No change in size.

How is a scale factor of one interpreted in scale drawings?

• It creates an exact copy of the original.

• It results in an enlargement.

• It changes the unit of measurement.

• It results in a reduction.

What was the longest base length of the actual trapezoid in millimeters?

• 100 mm

• 73 mm

• 10 cm

• 7 cm

What is the scale factor between the original scale drawing and the actual trapezoid?

• 1/4

• 73/100

• 4/1

• 100/73

What is the scale factor between the new scale drawing and the actual trapezoid?

• 400/73

• 73/400

• 4/1

• 1/4

How was the fraction 18 and 1/4 over 100 simplified?

• By multiplying by 100.

• By converting to a decimal.

• By multiplying by 1/100.

• By adding 1 to the numerator.

Why was the conversion to millimeters preferred in the exercise?

• To simplify the drawing process.

• To match the textbook examples.

• To make calculations easier.

• To avoid using decimals.