1. **State the problem:** We need to find the area of the garden, which is a rectangle with dimensions 15 m by 10 m. 2. **Identify the shape and dimensions:** The garden is a rectangle with length $15$ m and width $10$ m. 3. **Formula for area of a rectangle:** The area $A$ is given by $$A = \text{length} \times \text{width}$$ 4. **Calculate the area:** Substitute the given values: $$A = 15 \times 10 = 150$$ 5. **Interpretation:** The area of the garden is $150$ square meters. Note: The triangle inside the rectangle does not affect the total area of the garden since the garden is the entire rectangle.