1. 2.4 Applications of Ratios Mme DiMarco

2.  Learning Goal: Use ratios to solve problems Learning Goal

3.  Jolene makes a scale drawing of her home. She uses a scale of 5 cm to represent 1.5 m a)What is the ratio of a length in the drawing to the actual length? What does this ratio mean? a)Jolene measures her bedroom on the drawing. It is 16cm long. What is the actual length of Jolene’s bedroom? a)The house measures 18 m x 12 m. What are the dimensions of the scale drawing? Problem Solve

4. What is the ratio of a length in the drawing to the actual length? What does this ratio mean? Length in the drawing : actual length = 5 cm : 1.50 m = 5 cm : 150 cm = (5 cm ÷ 5 cm) : (150 cm ÷ 5 cm) = 1 : 30 Each 1 cm in the drawing represents 30 cm in the actual home. Solution When you write ratios of measurements, the units must be the same!!! Multiply 1.50 m by 100 to convert m to cm

5. Jolene measures her bedroom on the drawing. It is 16cm long. What is the actual length of Jolene’s bedroom? Scale: 1 cm drawing = 30 cm real life 16 x 30 = 480 cm = 4.8 m Solution 16 cm ? cm Drawing Bedroom

6. The house measures 18 m x 12 m. What are the dimensions of the scale drawing? Solution Scale: 1 cm drawing = 30 cm real life Length in drawing = 1800 cm ÷ 30 = 60 cm Width in drawing = 1200 cm ÷ 30 = 40 cm Therefore the dimensions of the scale drawing are 60 cm by 40 cm Width 12 m = 1200 cm Length 18 m = 1800 cm House

7.  Pages 60 – 61  Questions # 1 – 6 Homework