1. **Stating the problem:** We are given the formula for the area of a rectangle or parallelogram, which is $A = b \times h$, where $A$ is the area, $b$ is the base, and $h$ is the height. 2. **Formula explanation:** The area is found by multiplying the base length by the height. This works because the area measures how many square units fit inside the shape. 3. **Important rule:** Both $b$ and $h$ must be in the same units for the area to be correct. 4. **Example:** If $b = 5$ and $h = 3$, then $$A = 5 \times 3 = 15$$ So, the area is 15 square units. 5. **Summary:** To find the area using $A = b \times h$, multiply the base by the height.