1. **Problem statement:** Calculate the area of a triangular sail with base 6 cm and height 10 cm. 2. **Formula:** The area $A$ of a triangle is given by: $$A = \frac{1}{2} \times \text{base} \times \text{height}$$ 3. **Calculation:** Substitute base $B = 6$ cm and height $H = 10$ cm: $$A = \frac{1}{2} \times 6 \times 10$$ 4. **Intermediate step with cancellation:** $$A = \cancel{\frac{1}{2}} \times \cancel{6} \times 10 = 3 \times 10$$ 5. **Final area:** $$A = 30 \text{ cm}^2$$ 6. **Interpretation:** The area of the triangular sail is 30 square centimeters. 7. **Paint coverage:** Assuming the paint covers the entire outside of the sail, the amount of paint needed corresponds to the area, which is 30 cm².