EXERCISE 9.1 1. Convert these measurements to metres: \( \begin{array}{lll}\text { a) } 637 \mathrm{~mm} & \text { b) } 0,056 \mathrm{~km} & \text { c) } 350,7 \mathrm{~cm} \\ \text { 2. Convert these measurements to centimetres: } \\ \begin{array}{lll}\text { a) } 0,975 \mathrm{~km} & \text { b) } 54,2 \mathrm{~m} & \text { c) } 22,8 \mathrm{~mm}\end{array} \\ \text { 3. Name the polygons according to the number of sides. }\end{array} \)

Let's go through each part of the exercise step by step. ### 1. Convert these measurements to metres: a) \( 637 \, \text{mm} \) To convert millimetres to metres, we divide by 1000 (since 1 m = 1000 mm): \[ 637 \, \text{mm} = \frac{637}{1000} \, \text{m} = 0.637 \, \text{m} \] b) \( 0.056 \, \text{km} \) To convert kilometres to metres, we multiply by 1000 (since 1 km = 1000 m): \[ 0.056 \, \text{km} = 0.056 \times 1000 \, \text{m} = 56 \, \text{m} \] c) \( 350.7 \, \text{cm} \) To convert centimetres to metres, we divide by 100 (since 1 m = 100 cm): \[ 350.7 \, \text{cm} = \frac{350.7}{100} \, \text{m} = 3.507 \, \text{m} \] ### 2. Convert these measurements to centimetres: a) \( 0.975 \, \text{km} \) To convert kilometres to centimetres, we multiply by 100,000 (since 1 km = 100,000 cm): \[ 0.975 \, \text{km} = 0.975 \times 100000 \, \text{cm} = 97500 \, \text{cm} \] b) \( 54.2 \, \text{m} \) To convert metres to centimetres, we multiply by 100 (since 1 m = 100 cm): \[ 54.2 \, \text{m} = 54.2 \times 100 \, \text{cm} = 5420 \, \text{cm} \] c) \( 22.8 \, \text{mm} \) To convert millimetres to centimetres, we divide by 10 (since 1 cm = 10 mm): \[ 22.8 \, \text{mm} = \frac{22.8}{10} \, \text{cm} = 2.28 \, \text{cm} \] ### 3. Name the polygons according to the number of sides: - **3 sides**: Triangle - **4 sides**: Quadrilateral - **5 sides**: Pentagon - **6 sides**: Hexagon - **7 sides**: Heptagon - **8 sides**: Octagon - **9 sides**: Nonagon - **10 sides**: Decagon If you need more specific polygons or have any other questions, feel free to ask!