1. Problem 1: Find the scale of the building plan. Given: - Denah (plan) size = 40 cm x 25 cm - Actual building size = 120 m x 75 m 2. To find the scale, use the formula: $$\text{Scale} = \frac{\text{Length on plan}}{\text{Actual length}}$$ 3. Convert actual building size to cm (since plan is in cm): $$120\text{ m} = 120 \times 100 = 12000\text{ cm}$$ $$75\text{ m} = 75 \times 100 = 7500\text{ cm}$$ 4. Calculate scale for length and width: $$\text{Scale length} = \frac{40}{12000} = \frac{1}{300}$$ $$\text{Scale width} = \frac{25}{7500} = \frac{1}{300}$$ 5. Both scales are equal, so the scale is: $$1 : 300$$ --- 6. Problem 2: Find the difference in actual area between Garasi and Kamar Tidur. Given: - Scale = 1 : 150 - Garasi dimensions on plan: 2 cm x 1.5 cm - Kamar Tidur Utama dimensions on plan: 2 cm x 2.5 cm 7. Calculate actual dimensions by multiplying plan dimensions by scale factor 150: $$\text{Garasi actual} = 2 \times 150 = 300\text{ cm} = 3\text{ m}$$ (length) $$1.5 \times 150 = 225\text{ cm} = 2.25\text{ m}$$ (width) $$\text{Kamar Tidur actual} = 2 \times 150 = 300\text{ cm} = 3\text{ m}$$ (length) $$2.5 \times 150 = 375\text{ cm} = 3.75\text{ m}$$ (width) 8. Calculate actual areas: $$\text{Area Garasi} = 3 \times 2.25 = 6.75\text{ m}^2$$ $$\text{Area Kamar Tidur} = 3 \times 3.75 = 11.25\text{ m}^2$$ 9. Find the difference in area: $$11.25 - 6.75 = 4.5\text{ m}^2$$ Final answers: - Scale of the building plan is $1 : 300$. - The difference in actual area between Garasi and Kamar Tidur is $4.5\text{ m}^2$.